2.559 x 10^24 molecules present in 4.25 mol of CCl4.
To determine how many molecules are present in 4.25 mol of CCl4, you will need to use Avogadro's number.
Here are the steps:
1. Recall that Avogadro's number is 6.022 x 10^23, which represents the number of molecules in one mole of a substance.
2. Multiply the given amount of moles (4.25 mol) by Avogadro's number.
Calculation:
(4.25 mol) x (6.022 x 10^23 molecules/mol) = 2.559 x 10^24 molecules
So, there are 2.559 x 10^24 molecules present in 4.25 mol of CCl4.
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How many grams of thallium may be formed by the passage of 7,678 amps for 3.23 hours through an electrolytic cell that contains a molten Tl(I) salt.
Approximately 190 grams of thallium may be formed by the passage of 7,678 amps for 3.23 hours through an electrolytic cell that contains a molten Tl(I) salt. Faraday's Law, which states that the amount of substance produced by electrolysis is directly proportional to the quantity of electricity passed through the cell.
The formula for this is: moles of substance = (current x time) / (96500 x n) where current is measured in amperes, time is measured in seconds, n is the number of electrons transferred per mole of substance, and 96500 is the Faraday constant.
In this case, we are given the current (7,678 amps) and the time (3.23 hours, which is 11,628 seconds). We also know that the substance being electrolyzed is Tl(I) salt, which has a charge of +1. Therefore, n = 1.
Using the formula above, we can calculate the moles of thallium produced: moles of Tl = (7678 x 11628) / (96500 x 1) = 0.930 moles. To convert moles to grams, we need to multiply by the molar mass of thallium, which is 204.38 g/mol: grams of Tl = 0.930 moles x 204.38 g/mol = 190.04 grams
Therefore, approximately 190 grams of thallium may be formed by the passage of 7,678 amps for 3.23 hours through an electrolytic cell that contains a molten Tl(I) salt.
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Approximately 182 grams of thallium (Tl) may be formed by the passage of 7,678 amps for 3.23 hours through an electrolytic cell that contains a molten Tl(I) salt.
To calculate the amount of Tl formed, we need to use Faraday's law of electrolysis, which states that the amount of substance formed during electrolysis is directly proportional to the quantity of electricity passed through the cell.
The formula for Faraday's law is:
Amount of substance = (Current × Time × Atomic weight) / (Valency × Faraday constant)
In this case, the current is 7,678 amps, the time is 3.23 hours, the atomic weight of Tl is 204.38 g/mol, the valency is 1, and the Faraday constant is 96,485 coulombs/mol.
Plugging these values into the formula, we get:
Amount of substance = (7,678 × 3.23 × 204.38) / (1 × 96,485) = 182.04 g
Therefore, approximately 182 grams of thallium may be formed by the passage of 7,678 amps for 3.23 hours through an electrolytic cell that contains a molten Tl(I) salt.
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a spring system doing simple harmonic motion has an amplitude of 5.00 cm and a maximum speed of 30.0 cm/s. what is the displacement when its speed is 15.0 cm/s?
The displacement of the spring system when its speed is 15.0 cm/s is 3.75 cm.
The amplitude (A) of a spring system doing simple harmonic motion is the maximum displacement from the equilibrium position. In this case, the amplitude is given as 5.00 cm.
The maximum speed (v_max) occurs when the displacement is zero, and is equal to the amplitude multiplied by the angular frequency (ω) of the motion:
v_max = Aω
We can rearrange this equation to solve for the angular frequency:
ω = v_max / A
The displacement (x) of the spring system at any given time can be expressed as:
x = Acos(ωt)
where t is the time. To find the displacement when the speed is 15.0 cm/s, we need to first find the corresponding time.
At this speed, the velocity is half of the maximum velocity, so we can set:
15.0 cm/s = (1/2)v_max
Solving for v_max gives:
v_max = 30.0 cm/s
So, we have:
ω = v_max / A = (30.0 cm/s) / (5.00 cm) = 6.00 s⁻¹
Now, we can use the equation for displacement to find x when the velocity is 15.0 cm/s:
x = Acos(ωt)
15.0 cm/s = -Aωsin(ωt)
sin(ωt) = -(15.0 cm/s) / (Aω) = -0.50
At this point, we can use a calculator to find the value of the angle (ωt) that gives a sin of -0.50, which is approximately 30°.
Since we know that the displacement is at its maximum when the speed is zero, we can subtract the amplitude multiplied by the cosine of 30° to find the displacement at the given speed:
x = Acos(ωt) - A = (5.00 cm)cos(30°) - (5.00 cm) = 3.75 cm
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rank the following compounds in order of solubility in pure water (least to most soluble).a. caso4, ksp = 2.4 × 10–5b. mgf2, ksp = 6.9 × 10–9c. pbcl2, ksp = 1.7 × 10–5
The order of solubility in pure water (least to most soluble) is:
1. MgF2, Ksp = 6.9 × 10^–9 (least soluble)
2. PbCl2, Ksp = 1.7 × 10^–5
3. CaSO4, Ksp = 2.4 × 10^–5 (most soluble)
The solubility product constant (Ksp) is a measure of the equilibrium concentration of ions in a saturated solution of a compound.
A lower Ksp value indicates lower solubility, while a higher Ksp value indicates higher solubility.
From the given values of Ksp, it can be seen that MgF2 has the smallest Ksp value, indicating that it is the least soluble among the three compounds.
PbCl2 has a larger Ksp value than MgF2 but is smaller than CaSO4, indicating intermediate solubility. CaSO4 has the largest Ksp value, indicating that it is the most soluble among the three compounds.
Therefore, the order of solubility is b < c < a.
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Select ALL that are always TRUE for a spontaneous process.Group of answer choices∆H > 0 and ∆S < 0∆Suniverse > 0∆G < 0K = 1Q < K
∆G < 0 are always true for a spontaneous process.
A spontaneous process is one that occurs without the need for external intervention and leads to an increase in the entropy (disorder) of the universe. The spontaneity of a process is determined by the change in Gibbs free energy (∆G), which is given by the equation:
∆G = ∆H - T∆S
where ∆H is the change in enthalpy (heat) of the system, T is the temperature, and ∆S is the change in entropy of the system.
For a spontaneous process, ∆G must be negative, which means that the system is releasing free energy and the process is energetically favorable. Therefore, ∆G < 0 is always true for a spontaneous process.
The other options may or may not be true for a spontaneous process, depending on the specific conditions of the process. For example, if the process occurs at a low temperature, it may have a positive ∆S and a negative ∆H, which would make ∆G negative and the process spontaneous.
Similarly, if the reaction quotient Q is smaller than the equilibrium constant K, the process will be spontaneous, but if Q is larger than K, the process will be non-spontaneous. Therefore, these options cannot be universally true for a spontaneous process.
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The only statement that is always true for a spontaneous process is ∆G < 0. A spontaneous process is one that occurs without external intervention.
A spontaneous process is one that occurs without external intervention, and ∆G (the change in Gibbs free energy) is a thermodynamic parameter that determines whether a process is spontaneous or not.
If ∆G is negative, the process is spontaneous, and if ∆G is positive, the process is non-spontaneous. If ∆G is zero, the system is in equilibrium. Therefore, ∆G < 0 is always true for a spontaneous process.
The other statements listed may or may not be true for a spontaneous process depending on the specific conditions of the process. For example, ∆H > 0 and ∆S < 0 can still result in a spontaneous process if the temperature is high enough such that T∆S > ∆H, making ∆G < 0.
Similarly, ∆Suniverse > 0 is not always true for a spontaneous process since there can be cases where the entropy of the system decreases but the entropy of the surroundings increases by a larger amount, resulting in a decrease in ∆Suniverse.
Lastly, K = 1 and Q < K are related to the equilibrium constant, and the spontaneity of a process is not determined solely by the equilibrium constant.
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using any data you can find in the aleks data resource, calculate the equilibrium constant K at 25° C for the following reaction. N2 + O2 ---> 2NO
Round your answer to 2 signiicant digits.
The equilibrium constant (K) for the given reaction, N2 + O2 ⇌ 2NO, at 25°C.
To calculate the equilibrium constant, K, you need to know the concentrations (or partial pressures) of the reactants and products at equilibrium. The equilibrium constant expression for the reaction is written as:
K = [NO]^2 / ([N2] * [O2])
To determine the equilibrium constant, you would need experimental data, such as the concentrations or partial pressures of N2, O2, and NO at equilibrium. Once you have these values, substitute them into the equilibrium constant expression and calculate the value of K.
The equilibrium constant, K, is a dimensionless quantity that represents the ratio of the concentrations of products to reactants at equilibrium. It provides insight into the extent of the reaction and the relative concentrations of reactants and products in the equilibrium mixture.
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How many of the following species are diamagnetic? Cs, Zr2+, Al3+, Hg2+ A. 2 B. 3 C.4 D. 1 E.O
Cs and Zr²⁺ are paramagnetic, while Al³⁺ and Hg²⁺ are diamagnetic. Therefore, out of the given species, Al³⁺ and Hg²⁺ are diamagnetic, the correct answer is A. 2.
To determine whether a species is diamagnetic or not, we need to consider the electron configuration and the presence of unpaired electrons.
Cs: The electron configuration of Cs is [Xe]6s¹, which means it has one unpaired electron. Cs is paramagnetic, not diamagnetic.Zr²⁺: The electron configuration of Zr²⁺ is [Kr]4d². Zr²⁺ has two unpaired electrons and is paramagnetic, not diamagnetic.Al³⁺: The electron configuration of Al³⁺ is [Ne]2s² 2p⁶. Al3+ has no unpaired electrons and is diamagnetic.Hg²⁺: The electron configuration of Hg²⁺ is [Xe]4f¹⁴ 5d⁵. Hg²⁺ has no unpaired electrons and is diamagnetic.Learn more about diamagnetic: https://brainly.com/question/2272751
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Calculate the ?G°rxn using the following information.2 HNO3(aq) + NO(g) ? 3 NO2(g) + H2O(l) ?G°rxn = ??H°f (kJ/mol) -207.0 91.3 33.2 -285.8S°(J/mol•K) 146.0 210.8 240.1 70.0Determine the equilibrium constant for the following reaction at 498 K.2 Hg(g) + O2(g) ? 2 HgO(s)?H° = -304.2 kJ; ?S° = -414.2 J/KDetermine the equilibrium constant for the following reaction at 655 K.HCN(g) + 2 H2(g) ? CH3NH2(g)?H° = -158 kJ; ?S°= -219.9 J/KDetermine the equilibrium constant for the following reaction at 549 K.CH2O(g) + 2 H2(g) ? CH4(g) + H2O(g)?H° = - 94.9 kJ; ?S°= - 224.2 J/KEstimate ?G°rxn for the following reaction at 775 K.2 Hg(g) + O2(g) ? 2 HgO(s)?H°= -304.2 kJ; ?S°= -414.2 J/KCalculate ?S°rxn for the following reaction. The S° for each species is shown below the reaction.N2H4(l) + H2(g) ? 2 NH3(g)S° (J/mol•K) 121.2 130.7 192.8
To calculate the standard Gibbs free energy change (?G°rxn) for the given reaction, we can use the formula:
?G°rxn = ?Σn?G°f (products) - Σn?G°f (reactants)
where? Σn represents the sum of the coefficients of the products and reactants in the balanced chemical equation and ?G°f represents the standard Gibbs free energy of formation for each compound involved in the reaction. The values of ?H°f and S° for each compound are given in the table.
For the given reaction:
2 HNO3(aq) + NO(g) ? 3 NO2(g) + H2O(l)
Σn = 3 - 3 = 0
ΔG°rxn = (3 × ?G°f (NO2(g)) + ?G°f (H2O(l))) - (2 × ?G°f (HNO3(aq)) + ?G°f (NO(g)))
ΔG°rxn = (3 × 33.2 kJ/mol + (-237.1 kJ/mol)) - (2 × (-207.0 kJ/mol) + 91.3 kJ/mol)
ΔG°rxn = -225.1 kJ/mol
Therefore, the standard Gibbs free energy change for the given reaction is -225.1 kJ/mol.
The equilibrium constant (K) for a reaction can be calculated using the following formula:
K = e^(-ΔG°/RT)
where ΔG° is the standard Gibbs free energy change for the reaction, R is the gas constant (8.314 J/mol•K), and T is the temperature in Kelvin.
For the first reaction:
2 Hg(g) + O2(g) ? 2 HgO(s)
ΔH° = -304.2 kJ/mol
ΔS° = -414.2 J/K/mol
T = 498 K
ΔG° = ΔH° - TΔS°
ΔG° = -304.2 × 10^3 J/mol - 498 K × (-414.2 J/K/mol)
ΔG° = -304.2 × 10^3 J/mol + 205.7 × 10^3 J/mol
ΔG° = -98.5 × 10^3 J/mol
K = e^(-ΔG°/RT)
K = e^((-(-98.5 × 10^3 J/mol))/(8.314 J/mol•K × 498 K))
K = 1.72 × 10^-23
Therefore, the equilibrium constant for the first reaction at 498 K is 1.72 × 10^-23.
For the second reaction:
HCN(g) + 2 H2(g) ? CH3NH2(g)
ΔH° = -158 kJ/mol
ΔS° = -219.9 J/K/mol
T = 655 K
ΔG° = ΔH° - TΔS°
ΔG° = -158 × 10^3 J/mol - 655 K × (-219.9 J/K/mol)
ΔG° = -158 × 10^3 J/mol + 143.9 × 10^3 J/mol
ΔG° = -14.1 × 10^3 J/mol
K = e^(-ΔG°/RT)
K = e^((-(-14.1 × 10^3 J/mol))/(8.314 J/mol•K × 655 K))
K = 2
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The pH of 0.10 M NH3 is closest to11.132.875.138.87
The pH of 0.10 M NH3 is closest to 11.14.
Option(A)
The Kb value for ammonia, NH3, is 1.8 × 10^-5 at 25°C. The expression for the Kb value is:
Kb = [NH4+][OH-]/[NH3]
where [NH4+] is the concentration of ammonium ion, [OH-] is the concentration of hydroxide ion, and [NH3] is the concentration of ammonia. We can use the relationship Kw = Ka × Kb, where Kw is the ion product constant for water (1.0 × 10^-14 at 25°C) and Ka is the acid dissociation constant for NH4+.
Ka can be calculated from the following equation:
Ka = Kw/Kb = (1.0 × 10^-14)/(1.8 × 10^-5) = 5.56 × 10^-10
At equilibrium, the following reaction occurs:
NH3 + H2O ⇌ NH4+ + OH-
Since NH3 is a weak base, we can assume that its initial concentration is equal to its equilibrium concentration. Therefore, we can use the Kb expression to solve for [OH-]:
Kb = [NH4+][OH-]/[NH3] => [OH-] = Kb[NH3]/[NH4+] = (1.8 × 10^-5)(0.10)/[NH4+]
Since NH4+ is the conjugate acid of NH3, we can assume that it is formed by the reaction of NH3 with water:
NH3 + H2O ⇌ NH4+ + OH-
Therefore, the concentration of NH4+ is equal to [H3O+], and we can use the expression for the acid dissociation constant to solve for [H3O+]:
Ka = [NH4+][H3O+]/[NH3] => [H3O+] = Ka[NH3]/[NH4+] = (5.56 × 10^-10)(0.10)/[NH4+]
Since the solution is in equilibrium, [OH-][H3O+] = Kw = 1.0 × 10^-14. Therefore:
[OH-][H3O+] = (1.8 × 10^-5)(0.10)[NH4+]/[NH3] × (5.56 × 10^-10)(0.10)[NH3]/[NH4+] = 1.0 × 10^-14
Simplifying this equation, we get:
[NH4+][OH-] = 1.0 × 10^-14
Substituting [OH-] = (1.8 × 10^-5)(0.10)/[NH4+] into this equation, we get:
[NH4+] = 0.10/(1.8 × 10^-5)(1.8 × 10^-5)(0.10) = 3.086 M
Finally, we can calculate the pH of the solution using the expression:
pH = -log[H3O+] = -log[(5.56 × 10^-10)(0.10)/3.086] = 11.14 Option(A)
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The pH of 0.10 M NH3 is closest to 11.14. Option(A) Finally, we can calculate the pH of the solution using the expression: pH = -log[H3O+] = -log[(5.56 × 10^-10)(0.10)/3.086] = 11.14 Option(A).
The Kb value for ammonia, NH3, is 1.8 × 10^-5 at 25°C. The expression for the Kb value is:
Kb = [NH4+][OH-]/[NH3]
where [NH4+] is the concentration of ammonium ion, [OH-] is the concentration of hydroxide ion, and [NH3] is the concentration of ammonia. We can use the relationship Kw = Ka × Kb, where Kw is the ion product constant for water (1.0 × 10^-14 at 25°C) and Ka is the acid dissociation constant for NH4+.
Ka can be calculated from the following equation:
Ka = Kw/Kb = (1.0 × 10^-14)/(1.8 × 10^-5) = 5.56 × 10^-10
At equilibrium, the following reaction occurs:
NH3 + H2O ⇌ NH4+ + OH-
Since NH3 is a weak base, we can assume that its initial concentration is equal to its equilibrium concentration. Therefore, we can use the Kb expression to solve for [OH-]:
Kb = [NH4+][OH-]/[NH3] => [OH-] = Kb[NH3]/[NH4+] = (1.8 × 10^-5)(0.10)/[NH4+]
Since NH4+ is the conjugate acid of NH3, we can assume that it is formed by the reaction of NH3 with water:
NH3 + H2O ⇌ NH4+ + OH-
Therefore, the concentration of NH4+ is equal to [H3O+], and we can use the expression for the acid dissociation constant to solve for [H3O+]:
Ka = [NH4+][H3O+]/[NH3] => [H3O+] = Ka[NH3]/[NH4+] = (5.56 × 10^-10)(0.10)/[NH4+]
Since the solution is in equilibrium, [OH-][H3O+] = Kw = 1.0 × 10^-14. Therefore:
[OH-][H3O+] = (1.8 × 10^-5)(0.10)[NH4+]/[NH3] × (5.56 × 10^-10)(0.10)[NH3]/[NH4+] = 1.0 × 10^-14
Simplifying this equation, we get:
[NH4+][OH-] = 1.0 × 10^-14
Substituting [OH-] = (1.8 × 10^-5)(0.10)/[NH4+] into this equation, we get:
[NH4+] = 0.10/(1.8 × 10^-5)(1.8 × 10^-5)(0.10) = 3.086 M
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Arrange the compounds in order of decreasing magnitude of lattice energy:a. LiBr
b. KI
c. CaO.
The lattice energy is the energy released when 1 mole of a solid ionic compound is formed from its ions in the gas state. The magnitude of lattice energy depends on the charges of the ions and their sizes.
The correct order of decreasing magnitude of lattice energy is: c. CaO > b. KI > a. LiBr
CaO has the highest lattice energy because Ca2+ and O2- ions have the highest charges (2+ and 2-) and smallest sizes, which results in strong electrostatic attraction between them.
KI has the second-highest lattice energy because K+ and I- ions have higher charges than Li+ and Br-, and their sizes are larger than Ca2+ and O2-. However, the attraction between K+ and I- ions is stronger than Li+ and Br- ions due to their higher charges.
LiBr has the lowest lattice energy because Li+ and Br- ions have the smallest charges and larger sizes than Ca2+ and O2- or K+ and I- ions. The electrostatic attraction between them is the weakest among the three compounds. The compounds arranged in order of decreasing magnitude of lattice energy are CaO > LiBr > KI.
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. for [s] = 0.10 m and [e]0 = 1.0 x 10-5 m, calculate the rate of formation at 280 k.
The rate of formation for [s] = 0.10 m and [e]0 = 1.0 x 10-5 m at 280 K cannot be calculated without additional information about the reaction.
The rate law and activation energy of the reaction must be known to determine the rate of formation under specific conditions. The rate law describes the relationship between the concentrations of reactants and the rate of the reaction, and the activation energy is the minimum energy required for the reaction to occur. Without this information, it is impossible to calculate the rate of formation.
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how many moles of sulfur trioxide are formed from 3.0 moles of oxygen using the given balanced equation
6 moles of sulfur trioxide are formed from 3.0 moles of oxygen in the reaction 2SO₂+ O₂ → 2SO₃
A mole is defined as the amount of substance (atoms, molecules or ions) present in a particular species.
According to given data:
Number of moles of oxygen react = 3 mol
To find: Number of moles of SO₃ formed = ?
The balanced Chemical equation is given as:
2SO₂+ O₂ → 2SO₃
now we will compare the moles of oxygen and sulfur trioxide.
O₂ : SO₃
1 : 2
3 : 2/1×3 = 6 moles
Thus, 6 moles of SO₃ will formed.
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The complete question is
how many moles of sulfur trioxide are formed from 3.0 moles of oxygen using the given balanced equation 2SO₂+ O₂ → 2SO₃
determine the temperature of a reaction if k = 1.20 x 10⁻⁶ when ∆g° = 21.10 kj/mol.
Therefore, the temperature of the reaction is approximately 1,014 K.
The relationship between the equilibrium constant (K) of a reaction and the standard Gibbs free energy change (∆G°) at a given temperature (T) is given by the following equation:
∆G° = -RT ln(K)
where R is the gas constant (8.314 J/mol K) and ln represents the natural logarithm. Solving for temperature (T):
T = -∆G° / (R ln(K))
Plugging in the given values:
T = -21.10 kJ/mol / (8.314 J/mol K * ln(1.20 x 10^-6))
T = 1,014 K (to 3 significant figures)
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The percentage yield for the following reaction is 81.8%.
PCl3 + Cl2 → PCl5
What mass of PCl5 is expected from the reaction of 80.1 g PCl3 with excess chlorine?
The expected mass of PCl₅ from the reaction of 80.1 g of PCl₃ with excess chlorine is 121.34 g.
To calculate the expected mass of PCl₅ from the reaction, we need to consider the molar masses and the stoichiometry of the reaction. Here's how you can calculate it:
Determine the molar masses:
PCl₃ (Phosphorus trichloride) = 137.33 g/mol
Cl₂ (Chlorine) = 70.90 g/mol
PCl₅ (Phosphorus pentachloride) = 208.24 g/mol
Convert the given mass of PCl₃ to moles:
Moles of PCl₃ = Mass of PCl₃ / Molar mass of PCl₃
Moles of PCl₃ = 80.1 g / 137.33 g/mol
Use stoichiometry to determine the moles of PCl₅ formed:
From the balanced equation, we can see that the ratio of moles of PCl₃ to PCl₅ is 1:1. So, the moles of PCl₅ formed will be the same as the moles of PCl₃.
Calculate the expected mass of PCl₅:
Mass of PCl₅ = Moles of PCl₅ × Molar mass of PCl₅
Mass of PCl₅ = Moles of PCl₃ × Molar mass of PCl₅
Since the moles of PCl₅ formed is equal to the moles of PCl₃.
Substitute this value into the equation:
Mass of PCl₅ = Moles of PCl₃ × Molar mass of PCl₅
Mass of PCl₅ = (80.1 g / 137.33 g/mol) × 208.24 g/mol
Calculate the expected mass of PCl₅:
Mass of PCl₅ = 80.1 g × (208.24 g/mol / 137.33 g/mol)
Mass of PCl₅ ≈ 121.34 g
Therefore, the expected mass of PCl₅ from the reaction of 80.1 g of PCl₃ with excess chlorine is approximately 121.34 g.
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What is the vapor pressure of a solution that contains 2.60 mol glucose dissolved in 100.0 g of water? The vapor pressure of pure water is 2.4 kPa.Answer choices3.5 kPa0.28 kPa0.77 kPa1.6 kPa
The correct answer is 1.6 kPa.
To calculate the vapor pressure of a solution, we need to use Raoult's Law which states that the vapor pressure of a solution is directly proportional to the mole fraction of the solvent in the solution.
First, we need to calculate the mole fraction of water in the solution.
Moles of water = mass/molar mass = 100.0 g / 18.015 g/mol = 5.548 mol
Total moles in solution = 5.548 + 2.60 = 8.148 mol
Mole fraction of water = 5.548/8.148 = 0.680
Mole fraction of glucose = 2.60/8.148 = 0.320
Using Raoult's Law, we can calculate the vapor pressure of the solution:
vapor pressure = mole fraction of water x vapor pressure of pure water
vapor pressure = 0.680 x 2.4 kPa = 1.632 kPa
Therefore, the answer is 1.6 kPa.
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Weak acids make better buffers than strong acids because they have _____. conjugate bases of reasonable strength weak conjugate bases low ph values.
Weak acids make better buffers than strong acids because they have weak conjugate bases. Conjugate bases of reasonable strength weak conjugate bases low ph values.
A buffer is a solution that can resist changes in pH when an acid or a base is added to it. Weak acids have weak conjugate bases that are able to accept protons, which means that they can help to neutralize added base, preventing the pH from changing too drastically. Strong acids, on the other hand, have strong conjugate bases that do not readily accept protons, making them less effective as buffers.
Additionally, weak acids typically have a pH closer to neutral (around 4-6) compared to strong acids, which have a very low pH. This makes it easier to adjust the pH of a weak acid buffer solution without overshooting the desired pH range. Overall, weak acids with weak conjugate bases are better suited for use as buffers because they can help to maintain a stable pH range in a solution.
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a hydrogen atom absorbs radiation when its electron is excited to a higher energy level. stays in the ground state. makes a transition to a lower energy level. (b) is excited to a higher energy level.
(c) stays in the ground state.
A hydrogen atom absorbs radiation when its electron is excited to a higher energy level. stays in the ground state. makes a transition to a lower energy level. (b) is excited to a higher energy level. The correct option is (b).
A hydrogen atom absorbs radiation when its electron (b) is excited to a higher energy level. It will then (c) make a transition to a lower energy level at a later time, releasing the absorbed radiation in the process. If the electron does not absorb enough energy to reach a higher level, it will simply (c) stay in the ground state.
A hydrogen atom absorbs radiation when its electron is excited to a higher energy level. This occurs because the absorbed energy allows the electron to jump from its ground state to a higher energy level. The ground state is the lowest energy level, and when the electron makes a transition to a lower energy level, it releases energy in the form of radiation. So, the correct answer is (b) is excited to a higher energy level.
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A hydrogen atom absorbs radiation when its electron is excited to a higher energy level. When the electron absorbs energy from the radiation, it moves from a lower energy level to a higher one. This is known as an electronic transition. The energy of the absorbed radiation is equal to the energy difference between the initial and final energy levels. Once the electron reaches the higher energy level, it may eventually return to its original energy level, releasing the absorbed energy as radiation of a specific wavelength. This process is known as emission.
So, option (c) is the correct answer.
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Use the model to answer the question.
Examine the model.
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How does the process inside the box on the model influence the genes of an offspring?
The process creates new genes, which increases the genetic variation in the offspring.
The process exchanges genes, which results in genetic variation in the offspring.
The process duplicates chromosomes, which results in more genetic information in the offspring
The process removes chromosomes, which results in less genetic information in the offspring
The process inside the box on the model that influences the genes of an offspring is not clearly defined or described.
Without specific information about the process, it is difficult to determine its impact on the genes of an offspring. The options provided in the question are speculative and do not align with known biological processes. To accurately understand how a process influences the genes of an offspring, it is necessary to provide more details about the specific process in question. Genetic variation in offspring can arise through various mechanisms, including genetic recombination, mutation, and meiosis. Each process has distinct effects on the genetic information passed on to offspring.
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What is the molar solubility of Ag.PO in water? Ksp (Ag3PO4) = 1.4x10-16 (A) 1.1x10M (B) 4.8x10-SM (C) 5.2x10M (D) 6.8x10'M 1.LR.
The molar solubility of [tex]Ag_3PO_4[/tex] in water is [tex]4.78*10^{-6} M[/tex], which corresponds to answer (B).
The solubility product expression for silver phosphate ([tex]Ag_3PO_4[/tex]) is:
Ksp = [tex][Ag^+]^3[PO_4^{3-}][/tex]
Let x be the molar solubility of [tex]Ag_3PO_4[/tex] in water, then the equilibrium concentration of silver ions [[tex]Ag^+[/tex]] is also x, and the equilibrium concentration of phosphate ions [[tex]PO_4^{3-}[/tex]] is 3x, because the stoichiometry of the reaction is 1:3.
Substituting these values into the Ksp expression gives:
[tex]Ksp = x^{3(3x)} = 3x^4[/tex]
Solving for x:
[tex]x = (Ksp/3)^{(1/4)} = (1.4*10^{-16/3})^{(1/4)} = 4.78*10^{-6} M[/tex]
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Balance the following equations using the half-reaction method. Identify what is being oxidized and what is being reduced in each reaction: 1) M.O.' + a MAC (acidic solution
The balanced equation is: M.O.' + a MAC → b M.AC + [tex]cH_2O[/tex]. M.O.' is being reduced, and a MAC is being oxidized.
What are the balanced coefficients and oxidized/reduced species?In the given equation, M.O.' and a MAC react in an acidic solution to form b M.AC and [tex]c H_2O[/tex]. To balance the equation, we need to equalize the number of atoms on both sides and ensure that the charges are balanced.
To balance the equation using the half-reaction method, we start by identifying the oxidized and reduced species. The species that loses electrons is oxidized, while the species that gains electrons is reduced. In this case, M.O.' is being reduced because it is gaining electrons, and a MAC is being oxidized as it loses electrons.
Next, we balance the equation by separating the oxidation and reduction half-reactions. We balance the atoms, first considering those involved in the redox process. Then, we balance the charges by adding electrons to the side that needs them.
After balancing the atoms and charges, we can combine the half-reactions to obtain the balanced overall equation. The coefficients a, b, and c in the equation represent the stoichiometric coefficients needed to balance the number of molecules or ions involved in the reaction.
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Be sure to answer all parts. Complete the reactions to show how ethyl alcohol could be used to prepare CH3CN Ethyl alcohol o o NaCN [iji SOCI2; [2] NHz P4010 Na2Cr2O7, H2O H2SO4, heat PBrz or HBr Rxn Product O P4010 NaCN PBrz or HBO [1]1 SOCI2; [2] NH3 O O Na2Cr2O7, H20 H2S04, heat o This step is not necessary Rxn Product o P4010 O [1]1 SOC); [2] NH, NaCN Na2Cr2O7, H20 H2SO4, heat o This step is not necessary 0 PBrz or HBT Rxn Product o O [1]1 SOCI2; [2] NH3 P4010 This step is not necessary 0 PBrz or HBr NaCN Na2Cr2O7, H20 H2SO4, heat Rxn Product o O [1]1 SOCI2; [2] NH3 P4010 This step is not necessary PBrz or HBr NaCN Na2Cr2O7, H20 H2SO4, heat CH,CN
To prepare CH3CN (acetonitrile) from ethyl alcohol (CH3CH2OH), follow these steps:
1. First, oxidize ethyl alcohol to acetaldehyde using Na2Cr2O7, H2O, and H2SO4 under heat: CH3CH2OH + Na2Cr2O7 + H2SO4 (heat) → CH3CHO + byproducts
2. Next, convert acetaldehyde to ethyl bromide by reacting it with PBr3 or HBr: CH3CHO + PBr3 (or HBr) → CH3CH2Br + byproducts
3. After that, replace the bromine atom with a cyanide group using NaCN: CH3CH2Br + NaCN → CH3CH2CN + NaBr
4. Finally, eliminate ethylene using P4O10: CH3CH2CN + P4O10 → CH3CN + byproducts The overall reaction sequence can be summarized as: Ethyl alcohol → Acetaldehyde → Ethyl bromide → Ethyl cyanide → Acetonitrile
What is ethyl alcohol ?Ethyl Alcohol or Ethanol are liquid, clear and colorless goods, constituting an organic compound with the chemical formula C2H5OH, which is obtained both by fermentation and/or distillation as well as by chemical synthesis.
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when the following equation is balanced properly under acidic conditions, what are the coefficients of the species shown? h3aso3 clo3- h3aso4 cl-
To balance the equation properly under acidic conditions, we need to consider the oxidation states of the elements involved and apply the appropriate coefficients.
The balanced equation for the reaction between H3AsO3 and ClO3- to form H3AsO4 and Cl- is:
H3AsO3 + ClO3- -> H3AsO4 + Cl-
To balance the equation :
Balance the least abundant element first. In this case, arsenic (As) is present in both H3AsO3 and H3AsO4, so we can balance it last.
Balance oxygen (O) by adding H2O molecules as needed. In the reactants, there are three oxygen atoms in H3AsO3 and three in ClO3-, while in the products, there are four in H3AsO4. To balance oxygen, we add H2O on the reactant side:
H3AsO3 + ClO3- -> H3AsO4 + Cl- + H2O
Balance hydrogen (H) by adding H+ ions as needed. In the reactants, there are three hydrogen atoms in H3AsO3, while in the products, there are three in H3AsO4. Therefore, we need to balance hydrogen by adding three H+ ions on the reactant side:
H3AsO3 + ClO3- + 3H+ -> H3AsO4 + Cl- + H2O
Balance the charge by adding electrons (e-) as needed. In this case, the charges are already balanced.
Now, the balanced equation under acidic conditions is:
H3AsO3 + ClO3- + 3H+ -> H3AsO4 + Cl- + H2O
The coefficients of the species are:
H3AsO3: 1
ClO3-: 1
H+: 3
H3AsO4: 1
Cl-: 1
H2O: 1
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Calculate the ?G°rxn using the following information: 4HNO3 (g) + 5N2H4 (l) --> 7N2(g) + 12H2O (l) ?H= -133.9 50.6 -285.8 ?S= 266.9 121.2 191.6 70.0 ?H is in kJ/mol and ?S is in J/mol the answer needs to be in kJ I got -3298.2648 but that is wrong. Could someone please explain how to do this well please?
ΔG°rxn is calculated using the equation ΔG°rxn = ΔH°rxn - TΔS°rxn, where ΔH°rxn is the standard enthalpy change and ΔS°rxn is the standard entropy change.
How do you calculate the standard Gibbs free energy change (ΔG°rxn) for a given reaction?To calculate the standard Gibbs free energy change (ΔG°rxn) for the given reaction, we use the equation:
ΔG°rxn = ΔH°rxn - TΔS°rxn
where ΔH°rxn is the standard enthalpy change and ΔS°rxn is the standard entropy change.
Given:
ΔH°rxn = -133.9 kJ/mol + 50.6 kJ/mol - 285.8 kJ/mol = -368.7 kJ/mol
ΔS°rxn = 266.9 J/mol + 121.2 J/mol + 191.6 J/mol - 70.0 J/mol = 509.7 J/mol
To convert ΔS°rxn to kJ/mol, divide by 1000:
ΔS°rxn = 0.5097 kJ/mol
Assuming a temperature of 298 K, we can now calculate ΔG°rxn:
ΔG°rxn = -368.7 kJ/mol - (298 K * 0.5097 kJ/mol) = -368.7 kJ/mol - 152.0026 kJ/mol = -520.7026 kJ/mol
Therefore, the correct value of ΔG°rxn is -520.7026 kJ/mol. It appears that your calculated value of -3298.2648 kJ/mol is incorrect, likely due to an error in the calculation.
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calculate the number of molecules of acetyl-scoa derived from a saturated fatty acid with 20 carbon atoms. express your answer as an integer.
10 acetyl-CoA molecules will contain a total of 230 atoms: 20 carbon atoms, 30 oxygen atoms, 10 sulfur atoms, and 190 hydrogen atoms.
To calculate the number of molecules of acetyl-CoA derived from a saturated fatty acid with 20 carbon atoms, we need to first break down the fatty acid into individual acetyl-CoA molecules. Each acetyl-CoA molecule is produced by the breakdown of a two-carbon unit from the fatty acid chain. Therefore, a saturated fatty acid with 20 carbon atoms will produce 10 acetyl-CoA molecules.
Since acetyl-CoA is a molecule composed of atoms of carbon, hydrogen, oxygen, and sulfur, we cannot express the number of molecules as an integer. However, we can express the number of atoms in the 10 acetyl-CoA molecules as follows:
Each acetyl-CoA molecule contains 23 atoms: 2 carbon atoms, 3 oxygen atoms, 1 sulfur atom, and 19 hydrogen atoms.
Therefore, 10 acetyl-CoA molecules will contain a total of 230 atoms: 20 carbon atoms, 30 oxygen atoms, 10 sulfur atoms, and 190 hydrogen atoms.
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how many rings are present in c18h29bro3? this compound consumes 2 mol of h2 on catalytic hydrogenation. enter your answer in the provided box.
In the compound C18H29BrO3, there are 7 rings present. However, we don't have enough information about the connectivity of the atoms in the molecule. Therefore, it is not possible to give a detailed answer to this question without additional information.
Regarding the second part of the question, catalytic hydrogenation of c18h29bro3 consumes 2 mol of h2, which means that each molecule of the compound reacts with two molecules of hydrogen gas. This information can be used to calculate the stoichiometry of the reaction and the amount of product formed under specific conditions.
When the compound consumes 2 moles of H2 during catalytic hydrogenation, it means that two double bonds or other unsaturated bonds are present. The general formula for an acyclic alkane is CnH(2n+2). Since this compound has 18 carbons, the number of hydrogens in a saturated alkane would be 2(18) + 2 = 38.
Now, let's compare the actual number of hydrogens in the given compound with the expected number for a saturated alkane. The compound has 29 hydrogens, which is 9 less than the expected number (38 - 29 = 9).
Considering that it consumed 2 moles of H2, we can infer that there are 2 double bonds or other unsaturated bonds (each consuming 1 mole of H2) in the compound. This means there are 7 remaining unsaturations that can be attributed to rings. So, in the compound C18H29BrO3, there are 7 rings present.
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which pair of substances cannot form a buffered aqueous solution?18)a)hno3 and nano3b)hcn and kcnc)hf and nafd)hno2 and nano2e)nh3 and (nh4)2so4
The pair of substances that cannot form a buffered aqueous solution is (a) HNO₃ and NaNO₃ because a buffered solution is one that resists changes in pH when an acid or base is added to it.
To form a buffered solution, there needs to be a weak acid and its corresponding conjugate base or a weak base and its corresponding conjugate acid in the solution. HNO₃ is a strong acid, which means it completely dissociates in water to form H+ ions and NO₃⁻ ions. NaNO₃ is a salt of a strong acid and strong base, which also completely dissociates in water to form Na+ ions and NO₃⁻ ions.
Therefore, there are no weak acids or bases present in the solution, making it impossible to form a buffered solution. The other pairs of substances mentioned in the question, HCN and KCN, HF and NaF, HNO₂ and NaNO₂, and NH₃ and (NH₄)₂SO₄, all contain a weak acid and its corresponding conjugate base or a weak base and its corresponding conjugate acid, which means they can form buffered solutions.
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PLEASE HELP ME OUT!!!!
Which substance will have the greatest increase in temperature when equal masses absorb equal amounts of thermal energy? (Specific heats are given in parentheses. )
a. Water (4. 18 J/goC) c. Aluminum metal (0. 90 J/goC)
b. Ammonia gas (2. 1 J/goC) d. Solid calcium (0. 476 J/goC)
Among the given options, solid calcium will have the greatest increase in temperature when equal masses of these substances absorb equal amounts of thermal energy. This is because solid calcium has the lowest specific heat capacity, meaning it requires less heat energy to increase its temperature compared to the other substances.
The substance that will have the greatest increase in temperature when equal masses absorb equal amounts of thermal energy is the substance with the lowest specific heat capacity. Specific heat capacity is the amount of heat energy required to raise the temperature of a substance by a certain amount. Looking at the given options, we can compare the specific heat capacities of water, ammonia gas, aluminum metal, and solid calcium. Water has the highest specific heat capacity of 4.18 J/goC, which means it requires a large amount of heat energy to raise its temperature. Ammonia gas has a specific heat capacity of 2.1 J/goC, aluminum metal has a specific heat capacity of 0.90 J/goC, and solid calcium has the lowest specific heat capacity of 0.476 J/goC. Therefore, among the given options, solid calcium will have the greatest increase in temperature when equal masses of these substances absorb equal amounts of thermal energy. This is because solid calcium has the lowest specific heat capacity, meaning it requires less heat energy to increase its temperature compared to the other substances.
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The initial activity of a sample of the cesium isotope 137Cs is 135 mCi . When delivered to a hospital 14 hours later, its activity is 95 mCi.
A) What is the isotope's half life? (in hours)
B) If the minimum usable activity is 10mCi, how long after delivery at the hospital is the sample usable? (also in hours)
A) The sample will be usable for approximately 104.45 hours (or about 4.35 days) after delivery to the hospital. To find the half life of 137Cs, we can use the formula for radioactive decay:
A = A0(1/2)^(t/T), where A is the activity at time t, A0 is the initial activity, T is the half life, and (1/2)^(t/T) is the fraction of the original activity remaining at time t.
Plugging in the given values, we get:
95 = 135(1/2)^(14/T)
Dividing both sides by 135 and taking the natural logarithm of both sides, we can solve for T:
ln(95/135) = ln(1/2)^(14/T)
ln(95/135) = -(14/T)ln(2)
T = -14/(ln(95/135)/ln(2))
T = 30.17 hours
Therefore, the half life of 137Cs is approximately 30.17 hours.
B) We can use the same formula as above to find the time it takes for the activity to drop to 10mCi:
10 = 135(1/2)^(t/30.17)
Dividing both sides by 135 and taking the natural logarithm of both sides, we can solve for t:
ln(10/135) = -(t/30.17)ln(2)
t = -30.17ln(10/135)/ln(2)
t = 104.45 hours
Therefore, the sample will be usable for approximately 104.45 hours (or about 4.35 days) after delivery to the hospital.
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A) The radioactive decay equation, A = A0(1/2)(t/T), can be used to determine the half life of 137Cs. In this equation, A is the activity at time t, A0 is the starting activity, T is the half life, and (1/2)(t/T) is the percentage of the original activity still present at time t.
By entering the specified values, we obtain:
95 = 135(1/2)^(14/T)
We may find the value of T by taking the natural logarithm of both sides and dividing both sides by 135:
ln(95/135) = ln(1/2)^(14/T)
ln(95/135) = -(14/T)ln(2)
T = -14/(ln(95/135)/ln(2))
T equals 30.17 hours
As a result, 137Cs has a half life of about 30.17 hours.
B) The time it takes for the activity to decrease to 10 mCi can be calculated using the same calculation as above:
10 = 135(1/2)^(t/30.17)
by 135 and dividing both sides by, We can find t by using the natural logarithm of both sides:
ln(10/135) = -(t/30.17)ln(2)
t = -30.17ln(10/135)/ln(2)
t equals 104.45 hours
Therefore, after being delivered to the hospital, the sample will be useful for about 104.45 hours (or about 4.35 days).
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a solution has a proton, [h ], concentration of 2.00 × 10-6 m. what is the ph of the solution?
The pH of the solution is 5.70, which indicates that the solution is slightly acidic.
The pH of a solution is a measure of its acidity or basicity and is defined as the negative logarithm of the hydrogen ion concentration [H+].
The pH of a solution can be calculated using the formula: pH = -log[H+]. In this case, the [H+] concentration is 2.00 × [tex]10^{-6}[/tex] M.
Substituting this value into the formula, we get pH = -log(2.00 × [tex]10^{-6}[/tex]) = 5.70.
Therefore, the pH of the solution is 5.70, which indicates that the solution is slightly acidic.
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identify the type(s) of reaction(is) catalyzed by each of the following enzymes.
Isocitrate dehydrogenase catalyzes the conversion of isocitrate to alpha-ketoglutarate through oxidative decarboxylation.
1. Isocitrate dehydrogenase is an enzyme that is involved in the citric acid cycle, also known as the Krebs cycle or the tricarboxylic acid cycle.
2. The reaction catalyzed by isocitrate dehydrogenase involves the conversion of isocitrate, a six-carbon compound, to alpha-ketoglutarate, a five-carbon compound.
3. This reaction is an oxidative decarboxylation reaction, meaning that it involves the removal of a carbon atom from isocitrate in the form of carbon dioxide, and the transfer of electrons to an electron carrier molecule, NAD+.
4. The electrons transferred to NAD+ are used in the electron transport chain to generate ATP, the primary energy currency of cells.
5. Isocitrate dehydrogenase is an important regulatory enzyme in the citric acid cycle, as it controls the flux of carbon through the cycle and is sensitive to the energy status of the cell.
6. Mutations in the gene encoding isocitrate dehydrogenase have been implicated in a variety of human diseases, including cancer and neurodegenerative disorders.
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The probable question may be:
Identify The Type(S) Of Reaction(S) Catalyzed By Each Of The Following Enzymes. Isocitrate Dehydrogenase
Isocitrate dehydrogenase is a key enzyme in the citric acid cycle, which catalyses the oxidative decarboxylation of isocitrate, an essential step in cellular respiration.
Isocitrate dehydrogenase is an enzyme that is a part of the Krebs cycle, often known as the tricarboxylic acid (TCA) cycle or the citric acid cycle. This enzyme is essential for the process by which isocitrate is changed into -ketoglutarate during cellular respiration.
Isocitrate dehydrogenase is a catalyst for an oxidative decarboxylation process. It entails the decarboxylation of isocitrate, which removes a carbon dioxide molecule, and the concomitant transfer of electrons to a coenzyme like NAD+ or NADP+. As a result of this process, -ketoglutarate and NADH or NADPH are produced.
A crucial step in the citric acid cycle is the oxidative decarboxylation of isocitrate by isocitrate dehydrogenase because it produces -ketoglutarate, which enters the subsequent reactions of the cycle to produce ATP and other reduced electron carriers, as well as a high-energy electron carrier (NADH or NADPH).
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how many electrons are transferred in the following reaction? cr2o72– 14h 6cl– → 2cr3 3cl2 7h2o
In the given reaction, a total of 6 electrons are transferred when dichromate ion reacts to form chromium(III) and chlorine.
How many electrons participate in the reaction?To determine the number of electrons transferred in the given reaction, we need to balance the oxidation states of the elements involved.
In the dichromate ion (Cr₂ O₇ [tex]-2[/tex]), each chromium atom has an oxidation state of +6, while each oxygen atom has an oxidation state of -2. The overall charge of the ion is 2-.
In the products, each chromium atom in Cr₃ has an oxidation state of +3, while each chlorine atom in Cl₂ has an oxidation state of 0. The hydrogen atoms in H₂O have an oxidation state of +1, and each oxygen atom in H₂O has an oxidation state of -2.
By comparing the oxidation states of chromium in the reactant (Cr₂O₇ [tex]-2[/tex]) and the products (Cr₃ ), we can see that each chromium atom has gained 3 electrons.
Since there are two chromium atoms in the reactant, the total number of electrons transferred is:
2 chromium atoms × 3 electrons/atom = 6 electrons
Therefore, 6 electrons are transferred in the given reaction.
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