Answer:
Ainsi pour transformer, sous la pression atmosphérique, une masse de 1 kg d'eau pris à 20 °C en vapeur, l'énergie à fournir est égale à l'énergie fournie pour passer de 20 °C à 100 °C à l'état liquide soit 334 kJ puis à celle requise lors de la vaporisation à 100 °C soit 2256 kJ donc au total 2590 kJ.
Explanation:
draw the major organic product when each of the below reagents is added to 3,3-dimethylbutene.
The major organic product formed when each of the reagents is added to 3,3-dimethylbutene is as follows:
HBr: The major product is 3-bromo-3,3-dimethylbutane.
H₂SO₄ (concentrated sulfuric acid): The major product is 2,3-dimethylbut-2-ene (also known as 2,3-dimethylbutene or diisobutene).
HgSO₄ (mercuric sulfate) followed by H₂O: The major product is 3,3-dimethyl-2-butanol.
What is the major organic product?Addition of HBr to 3,3-dimethylbutene results in the electrophilic addition of the H-Br bond across the double bond, forming a bromine atom attached to the carbon at the site of the double bond. The major product is 3-bromo-3,3-dimethylbutane.
Concentrated sulfuric acid (H₂SO₄) acts as a dehydrating agent, removing a molecule of water from 3,3-dimethylbutene. This results in the formation of 2,3-dimethylbut-2-ene, where the double bond is shifted to the neighboring carbon atoms.
The addition of mercuric sulfate (HgSO₄) followed by water (H₂O) leads to oxymercuration-demercuration. The mercuric sulfate adds across the double bond to form a mercurinium ion intermediate, which is then reduced by water.
This process results in the formation of 3,3-dimethyl-2-butanol, where the hydroxyl group is added to one of the carbon atoms of the double bond.
It's important to note that these reactions are general representations, and the actual stereochemistry of the products may vary depending on the specific conditions and reaction conditions used.
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what’s another term for weak solutions
If u mean in terms of concentration, it will be 'Dilute'
One that is almost or entirely ionized in water is considered to be a strong acid or alkali. Nitric acid, sulfuric acid, and hydrochloric acid are a few examples. Weak solutions are not ionized in water.
What is a weak solution ?Bases provide a similar problem: a strong base is one that is completely ionized in solution. A weak base is one that is less than 100% ionized in solution.
The fundamental elements that do not completely ionize in water are known as weak bases. Ammonia is one substance that is a weak base. A portion of NH3 that dissolves in water separates into ammonium cation.
An acid that partially separates into its ions in water or an aqueous solution is referred to as a weak acid. On the other hand, in water, a strong acid completely dissociates into its ions. While the conjugate acid of a weak base is also a weak acid, the conjugate base of a weak acid is also a weak solution.
Thus, Weak solutions are not ionized in water.
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an analytical chemist is titrating 229.6 ml of a 1.100 m solution of acetic acid with a 0.7600 m solution of naoh.
The analytical chemist is performing a titration to determine the concentration of an acetic acid solution.
The chemist will add a known concentration of sodium hydroxide solution to the acetic acid solution until the equivalence point is reached, at which all of the acetic acid will have reacted with the sodium hydroxide.
By measuring the volume of sodium hydroxide solution required to reach the equivalence point, the chemist can calculate the concentration of the acetic acid solution.
In this specific titration, the acetic acid solution is 1.100 M and the sodium hydroxide solution is 0.7600 M, and the volume of the acetic acid solution used in the titration is 229.6 mL.
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What is the value of kb for the cyanide anion, CN^- ka(hcn) = 6×10^-10
The value of kb for the cyanide anion, CN^- can be calculated using the relationship: kb = kw/ka, where kw is the ion product constant for water, which is 1.0 x 10^-14 at 25°C.
Given that ka for HCN is 6 x 10^-10, we can first find the equilibrium constant for the dissociation of HCN into H+ and CN^-:
ka = [H+][CN^-]/[HCN]
At equilibrium, the concentration of CN^- is equal to the concentration of H+ since HCN is a weak acid. Thus, we can simplify the expression to:
ka = [CN^-]^2/[HCN]
Solving for [CN^-], we get:
[CN^-] = sqrt(ka*[HCN])
Substituting the given value of ka and assuming that the concentration of HCN is equal to the initial concentration (since it is a weak acid and does not fully dissociate), we get:
[CN^-] = sqrt(6 x 10^-10 * [HCN])
Now, we can use the relationship between kb and ka to find the value of kb:
kb = kw/ka = 1.0 x 10^-14/6 x 10^-10 = 1.67 x 10^-5
Therefore, the value of kb for the cyanide anion, CN^- is 1.67 x 10^-5.
To find the value of Kb for the cyanide anion (CN^-), we need to use the Ka for HCN and the Kw (ion product of water) constant. The given Ka for HCN is 6×10^-10.
Step 1: Write the relationship between Ka, Kb, and Kw:
Ka × Kb = Kw
Step 2: Insert the given values and solve for Kb:
Kw = 1×10^-14 (at 25°C)
Ka = 6×10^-10
Kb =?
(6×10^-10) × Kb = 1×10^-14
Step 3: Solve for Kb:
Kb = (1×10^-14) / (6×10^-10)
Kb = 1.67×10^-5
The value of Kb for the cyanide anion (CN^-) is 1.67×10^-5.
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magine that 500 ml of a 0.100 m solution of hoac(aq) is prepared. what will be the [oac–] at equilibrium in this solution if the acid dissociation constant ka(hoac) = 1.79 x 10–5?
The equilibrium concentration of OAc- in the 500 mL of 0.100 M solution of HOAc(aq) with a Ka(HOAc) of 1.79 x 10-5 will be approximately 0.00134 M..
To find the [OAc-] at equilibrium, we need to use the Ka expression and an ICE (Initial, Change, Equilibrium) table. The Ka expression for the dissociation of acetic acid (HOAc) is Ka = [H+][OAc-]/[HOAc]. Initially, [HOAc] = 0.100 M, [H+] = 0, and [OAc-] = 0. During the dissociation, [HOAc] will decrease by x, [H+] will increase by x, and [OAc-] will increase by x.
At equilibrium:
Ka = [H+][OAc-]/[HOAc]
1.79 x 10-5 = (x)(x)/(0.100-x)
We can assume that x is small compared to 0.100, so we can simplify the equation to:
1.79 x 10-5 = (x^2)/0.100
Now, solve for x:
x^2 = 1.79 x 10-5 * 0.100
x^2 = 1.79 x 10-6
x ≈ 0.00134
Since x represents the change in [H+] and [OAc-], the equilibrium concentration of OAc- is approximately 0.00134 M.
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H 2(g) +O 2(g) H 2 O (g) If 8. 6 L of H 2 reacted with 5. 3 L of O 2 at STP, what is the volume (in liters) of the gaseous water collected?
To determine the volume of gaseous water collected use the balanced chemical equation and the concept of stoichiometry. The balanced equation for the reaction is 2H2(g) + O2(g) → 2H2O(g).
From the equation, we can see that 2 moles of H2 react with 1 mole of O2 to produce 2 moles of H2O.
Given that we have 8.6 L of H2 and 5.3 L of O2 at STP (Standard Temperature and Pressure), we can use the ideal gas law to convert the volumes to moles.
At STP, 1 mole of any ideal gas occupies 22.4 L.
Moles of H2 = 8.6 L / 22.4 L/mol = 0.3846 mol
Moles of O2 = 5.3 L / 22.4 L/mol = 0.2366 mol
Based on the balanced equation, we can see that the ratio of moles of H2O to O2 is 2:1. Therefore, the moles of H2O produced will be half the moles of O2.
Moles of H2O = 0.2366 mol / 2 = 0.1183 mol
Now, to convert the moles of H2O to volume, we use the ideal gas law again: Volume of H2O = Moles of H2O × 22.4 L/mol = 0.1183 mol × 22.4 L/mol = 2.647 L. Therefore, the volume of gaseous water collected is approximately 2.647 liters.
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calculate the boiling point (in degrees c) of a solution made by dissolving 3.71 g of fructose (c6h12o6) in 87 g of water. the kbp of the solvent is 0.512 k/m and the normal boiling point is 373 k.
Boiling point = Normal boiling point + ΔT = 373 K + (3.71 g/180.16 g/mol) * (0.512 K/m) / (0.087 kg) = 374.12 K.
To calculate the boiling point of the solution, we'll first find the molality (m) of fructose.
Molality is defined as moles of solute per kilogram of solvent.
1. Calculate moles of fructose: (3.71 g) / (180.16 g/mol) = 0.0206 mol
2. Convert grams of water to kilograms: 87 g = 0.087 kg
3. Calculate molality: (0.0206 mol) / (0.087 kg) = 0.237 m
Next, we'll use the molality and the Kbp (0.512 K/m) to find the change in boiling point (ΔT).
4. Calculate ΔT: (0.237 m) * (0.512 K/m) = 0.121 K
Finally, add ΔT to the normal boiling point (373 K).
5. Boiling point = 373 K + 0.121 K = 374.12 K
The boiling point of the solution is 374.12 K, or approximately 101.0°C.
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The boiling point of the solution would be 100.34°C.
To calculate the boiling point elevation, we can use the formula:
ΔTb = Kbp x molality
where ΔTb is the boiling point elevation, Kbp is the boiling point elevation constant of the solvent, and molality is the concentration of the solution in terms of moles of solute per kilogram of solvent.
First, we need to calculate the molality of the solution. We know the mass of fructose (3.71 g) and the mass of water (87 g). We can convert the mass of fructose to moles by dividing by its molar mass:
moles of fructose = 3.71 g / 180.16 g/mol = 0.0206 mol
Then, we can calculate the molality:
molality = moles of fructose / mass of water in kg
molality = 0.0206 mol / 0.087 kg = 0.237 mol/kg
Now we can calculate the boiling point elevation:
ΔTb = Kbp x molality
ΔTb = 0.512 K/m x 0.237 mol/kg = 0.1216 K
Finally, we can calculate the boiling point of the solution:
Boiling point of solution = normal boiling point of solvent + ΔTb
Boiling point of solution = 373 K + 0.1216 K = 373.12 K
We can convert the boiling point to Celsius by subtracting 273.15:
Boiling point of solution = 373.12 K - 273.15 = 100.34°C
Therefore, the boiling point of the solution is 100.34°C.
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Calculate the standard enthalpy of reaction
for the reaction 2 Na (s) + 2 H₂O (l)
2 NaOH (aq) + H₂ (g), Standard enthalpies
formation are -285.8 kJ/mol for H₂O and -470. 11 kJ/mol for NaOH (aq).
Answer:
-368.62 kJ/mol
Explanation:
[(2 x - 470.11 kJ/mol) ( 0kJ/mol)] - [ 2 x -285.8 kJ/mol) (2x 0 kj/mol)] = -368.62 kJ/mol
Calculate the solubility of silver phosphate, Ag3PO4, in pure water. Ksp = 2.6 x 10-18 O 1.5 x 10-5 M O 4.0 x 10-5 M O 4.0 x 10-6 M O 1.8 x 10-5 M O < 1.0 x 10-5M
The solubility of silver phosphate, Ag₃PO₄, in pure water is approximately 2.6 x 10⁻⁶ mol/L.
Solubility is the maximum amount of solute that can be dissolved in a given amount of solvent at a particular temperature and pressure, usually expressed in units of grams per liter (g/L) or moles per liter (mol/L).
The solubility of Ag₃PO₄ can be calculated using the Ksp expression;
[tex]K_{sp}[/tex] = [Ag⁺]³ [PO₄³⁻]
Let x be the solubility of Ag₃PO₄ in mol/L. Then, at equilibrium, the concentrations of Ag⁺ and PO₄³⁻ ions will be x mol/L. Therefore;
[tex]K_{sp}[/tex] = (x)³ (x)³ = x⁶
Solving for x, we get;
x = [tex](Ksp)^{(1/6)}[/tex] = (2.6 x 10⁻¹⁸[tex])^{1/6}[/tex]
≈ 2.6 x 10⁻⁶ mol/L
Therefore, the solubility is 2.6 x 10⁻⁶ mol/L.
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.Write chemical equations to represent each of the following & identify the type of reaction that occurs.
1. reaction of cesium metal with chlorine gas
2. formation of sodium peroxidefrom reactants in elemental form
3. reaction of magnesium and brominegas
4. reaction of calcium with nitrogen gas followed by additional step of water workup.
5. combustion of potassium to form potassium superoxide
6. combustion of lithium metal in oxygen gas
7. lithium metal heated in the presence of hydrogen gas and subsequently treated with water
8. production of titanium metal throughthe reduction of titanium(IV) chloride with sodium metal
The production of titanium metal through the reduction of titanium(IV) chloride with sodium metal involves a redox reaction. Titanium(IV) chloride is a compound that contains titanium in the +4 oxidation state, while sodium metal is an element with a tendency to lose electrons to form Na+ ions.
The reduction of titanium(IV) chloride involves the transfer of electrons from sodium metal to titanium(IV) ions.
The chemical equation for the reaction is:
TiCl4 + 4Na → Ti + 4NaCl
This equation shows that one molecule of titanium(IV) chloride reacts with four atoms of sodium to produce one atom of titanium and four molecules of sodium chloride.
The reduction of titanium(IV) chloride with sodium metal is an example of a single-displacement reaction. In this type of reaction, one element displaces another element in a compound to form a new compound and a different element. In this case, sodium metal displaces the titanium(IV) ion in titanium(IV) chloride to form titanium metal and sodium chloride.
In summary, the production of titanium metal through the reduction of titanium(IV) chloride with sodium metal involves a redox reaction in which titanium(IV) ions are reduced to titanium metal by sodium metal. The chemical equation for the reaction is TiCl4 + 4Na → Ti + 4NaCl, and the reaction is a single-displacement reaction.
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(e) based on the data, the student claims that the catalyzed reaction has zeroth-order kinetics. do you agree with the student’s claim? justify your answer.
Without access to such data, it is not possible to agree or disagree with the student's claim regarding zeroth-order kinetics.
However, in general, if the reaction rate is independent of the concentration of the reactant(s) and only depends on the concentration of the catalyst, then the reaction is said to have zeroth-order kinetics with respect to the reactant(s) and first-order kinetics with respect to the catalyst. If the data shows a constant rate of reaction despite changes in the concentration of the reactants, then the student's claim that the reaction has zeroth-order kinetics may be valid. However, without the specific data and context, it is not possible to give a definitive.
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Determine whether the following compounds are organometallic. Explain your answer. (0) Cacz (ii) CH3COONa (iii) Cr(CO) (iv) B(C2H5)3
The compounds (ii) CH₃COONa and (iii) Cr(CO) are not organometallic, while compounds (0) Cacz and (iv) B(C₂H₅)₃ are organometallic.
Which compounds among Cacz, CH₃COONa, Cr(CO), and B(C₂H₅)₃ are organometallic?Organometallic compounds contain a direct bond between a carbon atom and a metal atom. In the given compounds, Cacz and B(C₂H₅)₃ fulfill this criterion and are considered organometallic.
Cacz refers to a carbanion complex with a direct carbon-calcium bond. B(C₂H₅)₃, on the other hand, is boron triethyl, where the boron atom is bonded to three ethyl groups. These compounds exhibit unique reactivity and are widely used in organic synthesis and catalysis.
However, CH₃COONa (sodium acetate) and Cr(CO) (chromium carbonyl) do not have direct carbon-metal bonds and, therefore, are not organometallic.
Sodium acetate is a salt composed of sodium ions and acetate ions, while chromium carbonyl consists of chromium and carbon monoxide ligands. These compounds do not possess the characteristic carbon-metal bond found in organometallic compounds.
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2. how many grams of khp, khcsh.os, are needed to react with 38.56 ml of a
0.2500 m sodium hydroxide solution?
To determine the number of grams of KHP (potassium hydrogen phthalate, C8H5KO4) needed to react with 38.56 mL of a 0.2500 M sodium hydroxide (NaOH) solution,
We can use stoichiometry and the balanced chemical equation between KHP and NaOH. The balanced equation is:
KHP + NaOH → KNaC8H4O4 + H2O
From the balanced equation, we can see that the stoichiometric ratio between KHP and NaOH is 1:1. This means that one mole of KHP reacts with one mole of NaOH.
First, we need to calculate the number of moles of NaOH:
Volume of NaOH solution = 38.56 mL = 0.03856 L (converted to liters)
Molarity of NaOH solution = 0.2500 M
Number of moles of NaOH = Volume × Molarity = 0.03856 L × 0.2500 mol/L = 0.00964 mol
Since the stoichiometric ratio between KHP and NaOH is 1:1, the number of moles of KHP needed is also 0.00964 mol.
To calculate the mass of KHP, we need to know the molar mass of KHP, which is 204.23 g/mol.
Mass of KHP = Number of moles × Molar mass = 0.00964 mol × 204.23 g/mol = 1.969 g. Therefore, approximately 1.969 grams of KHP are needed to react with 38.56 mL of a 0.2500 M NaOH solution.
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For which slightly soluble substance will the addition of HCl to its solution have no effect on its solubility? a. AgBr(s) b. PbF2(s) c. MgCO3(s) d. Cu(OH)2(s)
The substance for which the addition of HCl to its solution will have no effect on its solubility is [tex]PbF_2[/tex](s) (option b).
The addition of HCl to a solution can affect the solubility of some slightly soluble substances by reacting with them to form a more soluble compound. The solubility of a substance may increase or decrease depending on the nature of the reaction.
a. AgBr(s) - The addition of HCl to a solution of AgBr will decrease its solubility because AgBr will react with HCl to form a more soluble compound, silver chloride (AgCl).
b. [tex]PbF_2[/tex](s) - The addition of HCl to a solution of [tex]PbF_2[/tex] will have no effect on its solubility because [tex]PbF_2[/tex] is insoluble in water and does not react with HCl.
c. [tex]MgCO_3[/tex](s) - The addition of HCl to a solution of [tex]MgCO_3[/tex] will decrease its solubility because [tex]MgCO_3[/tex] will react with HCl to form a more soluble compound, magnesium chloride ([tex]MgCl_2[/tex]), and carbon dioxide ([tex]CO_2[/tex]).
d. [tex]Cu(OH)_2[/tex](s) - The addition of HCl to a solution of [tex]Cu(OH)_2[/tex] will decrease its solubility because [tex]Cu(OH)_2[/tex] will react with HCl to form a more soluble compound, copper chloride ([tex]CuCl_2[/tex]), and water ([tex]H_2O[/tex]).
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how many unpaired d-electrons are there in the octahedral high-spin cobalt(iii) complex ion, [cof6]3-? (small ligand field splitting)
There are three unpaired d-electrons in the octahedral high-spin cobalt(iii) complex ion, [CoF6]3- (small ligand field splitting).
In an octahedral high-spin cobalt(iii) complex with small ligand field splitting, the d-electrons occupy the t2g and eg orbitals. As all six ligands are small, they generate a weak ligand field, which results in the energy difference between the t2g and eg orbitals being small, allowing for a high-spin configuration. Cobalt(iii) has five d-electrons, which fill the t2g orbitals first with three electrons, leaving two unpaired electrons in the eg orbitals. Therefore, the complex has three unpaired d-electrons. There are three unpaired d-electrons in [CoF6]3- due to high-spin configuration and weak ligand field splitting, causing a small energy difference between the t2g and eg orbitals.
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which element has a smaller atomic radius than strontium (Sr)?
it is tecnically magnesium,
Answer:
barium is the answer
What characteristics do degenerate orbitals have? [select all that apply]A. All degenerate orbitals have the same magnetic quantum number m. B. Degenerate orbitals always have the same number of electrons in them. C. Degenerate orbitals are immoral and corrupt. D. Degenerate orbitals have the same energy. E. All orbitals belonging to the same atom are degenerate with respect to one another.
Degenerate orbitals have the following characteristics: Degenerate orbitals have the same energy.
So, the correct answer is D.
Degenerate orbitals are orbitals that have the same energy level. This means that electrons in these orbitals have the same potential energy.
Characteristics of degenerate orbitals include having the same energy, and they are all identical in shape and size.
Additionally, degenerate orbitals have different values of the magnetic quantum number, m, but they share the same principal quantum number and azimuthal quantum number.
However, degenerate orbitals do not always have the same number of electrons in them, as this depends on the specific configuration of the atom.
Finally, it is important to note that degenerate orbitals only exist within the same subshell, and not across different subshells. It is also incorrect to say that degenerate orbitals are immoral and corrupt.
Hence, the correct answer is D.
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which is a plausible solution to human activities contributing to increasing amounts of carbon dioxide in the atmosphere? a use only alternative energies for the production of electricity. b require all new automobiles manufactured to run on electricity rather than gasoline. c plant more trees and decrease deforestation practices so that more carbon dioxide can be absorbed from the atmosphere. d require everybody to use mass transportation or methods of transportation that do not require burning fossil fuels, such as riding bicycles.
A plausible solution to human activities contributing to increasing amounts of carbon dioxide in the atmosphere would be to implement a combination of solutions that target various sectors of society. Option A, using alternative energies for the production of electricity, is a good start.
It reduces the amount of carbon emissions from power plants. However, it does not solve the issue of carbon emissions from transportation, which is a significant contributor to the problem.
Option B, requiring all new automobiles to run on electricity, is also a good solution. It will significantly reduce carbon emissions from transportation, which is a significant contributor to the problem. However, it does not solve the issue of carbon emissions from existing vehicles.
Option C, planting more trees and decreasing deforestation practices, is a great solution. Trees absorb carbon dioxide from the atmosphere, which reduces the amount of greenhouse gases in the air. However, it is a long-term solution that requires consistent efforts over time.
Option D, requiring everybody to use mass transportation or methods of transportation that do not require burning fossil fuels, such as riding bicycles, is also a great solution. It reduces carbon emissions from transportation and encourages people to adopt a healthier lifestyle. However, it may not be feasible for everyone, especially those who live in rural areas with limited transportation options.
Therefore, a combination of solutions is necessary to reduce carbon emissions and combat climate change. These solutions should include alternative energy sources, electric vehicles, reforestation efforts, and incentives for individuals to use low-carbon transportation options.
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[3]
3. Given that AT = -7.0 K for a reaction involving 0.20 mol of reactant and C = 410 J/K
for the calorimeter and contents, calculate AH in Kj.mol-¹ for the reaction.
[4]
Okay, let's solve this step-by-step:
1) AT = -7.0 K (given)
2) C = 410 J/K (given)
3) Mass of reactant = 0.20 mol (given)
4) To convert temperature change (K) to energy change (J): Energy change = Heat capacity x Temperature change
So in this case: Energy change = 410 J/K x -7.0 K = -2870 J
5) To get enthalpy change per mole (AH), we divide the total energy change by the number of moles of reactant:
-2870 J / 0.20 mol = -14350 J/mol
Therefore, AH = -14350 J/mol.
Let me know if you have any other questions!
To determine the enthalpy change (∆H) for the reactant, first use the relationship q = C × ∆T to calculate the heat exchange in the reaction. Then, convert the resulting value from joules to kilojoules. Finally, divide by the number of moles of the reactant to find ∆H. The enthalpy change for the reaction is -14.35 kj/mol.
Explanation:This chemistry problem involves the use of thermochemical equations and calorimetry principles. Given in the problem, the change in temperature (∆T) is -7.0 K, the heat capacity (C) of the calorimeter and contents is 410 J/K, and a mole of reactant involved is 0.20 mol. Let's use the equation q = C × ∆T to calculate the heat absorbed or released in a reaction where q is the heat gained or lost, C is the calorimeter’s heat capacity, and ∆T is the change in temperature. Hence, the heat exchange (q) = 410 J/K * -7.0 K = -2870 Joules.
This value is negative because it's giving off heat (exothermic). We see that the value obtained is in joules, but we need the output in Kj. 1 Joule is 1x10^-3 Kj, so -2870 Joules is -2.87 Kj. To find ∆H (Enthalpy change), we divide the heat exchanged by the amount of moles. Therefore, ∆H = q/n = -2.87 Kj / 0.20 moles = -14.35 Kj.mol⁻¹. So the enthalpy change for the reaction is -14.35 Kj.mol⁻¹.
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15. a saturated solution of lead (ii) iodide, pbi2 has an iodide concentration of 3.0 × 10-3 mol/ l. calculate the molar solubiltiy of pbi2.
The molar solubility of PBI2 can be calculated using the concentration of iodide ions in a saturated solution of PBI2. Since PBI2 dissociates in water to form lead ions (Pb2+) and iodide ions (I-), we can write the dissolution equation as follows:
PbI2 (s) ⇌ Pb2+ (aq) + 2I- (aq)
The solubility product expression for PBI2 can be written as:
Ksp = [Pb2+][I-]^2
Since the solution is saturated, the concentrations of Pb2+ and I- ions are in equilibrium with the solid PBI2. Therefore, we can assume that the concentration of Pb2+ ions is negligible and that the concentration of I- ions is equal to the concentration of iodide ions in the saturated solution, which is 3.0 × 10-3 mol/L.
Substituting these values into the solubility product expression:
Ksp = (3.0 × 10-3 mol/L)^2 = 9.0 × 10-9
Solving for the molar solubility of PBI2:
Ksp = [Pb2+][I-]^2 = (x)(3.0 × 10-3 mol/L)^2
x = Ksp / [I-]^2 = 9.0 × 10-9 / (3.0 × 10-3 mol/L)^2 = 3.0 × 10-6 mol/L
Therefore, the molar solubility of PBI2 is 3.0 × 10-6 mol/L.
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How many representative particles are in 8.56 x 10^-3 mol sodium chloride
There are approximately 5.16 x10^{21}representative particles in 8.56 x 10^{-3} mol of sodium chloride.
To determine the number of representative particles in a given amount of substance, we need to use Avogadro's number, which is approximately 6.022 x 10^{23} representative particles per mole.
Given that there are 8.56 x10^{-3}mol of sodium chloride, we can calculate the number of representative particles as follows:
Number of representative particles = amount in moles × Avogadro's number
Number of representative particles = 8.56 x10^{-3}mol × 6.022 x10^{23}particles/mol
Number of representative particles ≈ 5.16 x10^{21}particles
Therefore, there are approximately 5.16 x[tex]10^{21}[/tex]representative particles in 8.56 x10^{-3} mol of sodium chloride. This calculation is based on the understanding that one mole of any substance contains Avogadro's number of particles, which is a fundamental concept in chemistry.
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2H₂ + O₂ → 2H₂O
Convert grams of H₂ to grams of H₂O.
a. 44,680 g H₂O
b. 5,000 g H₂O
c. 345676543 g H₂O
d. 3335 g H₂O
Answer:
500100 benswuer kers olá Marilene
The mass of H₂O is 44,680 g for the given reaction 2H₂ + O₂ → 2H₂O. Therefore, the correct option is option A.
What is mass?In physics, mass is a quantitative measurement of inertia, a basic characteristic of all matter. It essentially refers to a body of matter's resistance to changing its speed or location in response to the force that is applied. The change caused by either an applied force is smaller the more mass a body has.
The kilogramme, which is defined approximately equal to 6.6 × 10⁻³⁴ joule second in terms of Planck's constant, is the unit of mass inside the Worldwide System of Units (SI). A joule is equivalent to one kilogramme multiplied by one square metre per second. The mass of H₂O is 44,680 g for the given reaction 2H₂ + O₂ → 2H₂O.
Therefore, the correct option is option A.
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An electron in a bohr model hydrogen atom jumps from the 2nd energy level to the 4th level. calculate the wavelength of the photon such a jump produces.
The wavelength of the photon produced when an electron in a Bohr model hydrogen atom jumps from the 2nd to the 4th energy level is approximately 1.22 x 10^-7 meters.
To calculate the wavelength of the photon, we need to find the energy difference between the two energy levels and use the formula E = hf, where E is the energy, h is Planck's constant, and f is the frequency.
The energy difference between energy levels in a hydrogen atom is given by the formula: ΔE = 13.6 * (1/n1^2 - 1/n2^2) eV. In our case, n1=2 and n2=4.
Calculating ΔE, we get approximately -3.03 eV. Converting this to joules, we have ΔE ≈ -4.85 x 10^-19 J.
Now, we use the formula E = hf, where h is Planck's constant (6.63 x 10^-34 Js), and the speed of light c = 3 x 10^8 m/s. By substituting the values and solving for the wavelength λ, we get λ ≈ 1.22 x 10^-7 meters.
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(Cr2O7)2{-} + H2O2 + H{+} = CrO5 + H2O - Chemical Equation Balancer
The balanced chemical equation represents the stoichiometry of the reaction and ensures that the number of atoms of each element on both sides of the equation is equal, which is necessary for the conservation of mass during a chemical reaction.
The balanced chemical equation for the reaction of dichromate ion [(Cr2O7)2-] with hydrogen peroxide (H2O2) and hydrogen ion (H+) to produce chromate ion (CrO5) and water (H2O) can be written as:
2(Cr2O7)2- + 8H2O2 + 12H+ → 4CrO5 + 16H2O
In this reaction, the dichromate ion is reduced to chromate ion and hydrogen peroxide is oxidized to water. The reaction takes place in an acidic medium, which provides hydrogen ions to protonate the peroxide ion and facilitate the reduction of dichromate ion. The balanced equation shows that two molecules of dichromate ion, eight molecules of hydrogen peroxide, and twelve hydrogen ions are required to produce four molecules of chromate ion and sixteen molecules of water.
Overall, the balanced chemical equation represents the stoichiometry of the reaction and ensures that the number of atoms of each element on both sides of the equation is equal, which is necessary for the conservation of mass during a chemical reaction.
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Which member of each pair is more metallic? (a) Na or Cs (b) Mg or Rb (c) As or N
(a) Cs is more metallic than Na.
(b) Rb is more metallic than Mg.
(c) N is less metallic than As.
Metallic character refers to the ability of an atom to lose electrons and form positive ions. Elements with more electrons in their outermost shell tend to have higher metallic character.
In pair (a), Cs has a larger atomic radius and more shielding electrons than Na, making it easier for Cs to lose electrons and become a positive ion, indicating higher metallic character.
In pair (b), Rb has a larger atomic radius and more shielding electrons than Mg, making it easier for Rb to lose electrons and become a positive ion, indicating higher metallic character.
In pair (c), As has one more electron than N in the same energy level, leading to a smaller atomic radius and less shielding electrons for As. Therefore, N is less electronegative and has higher metallic character compared to As.
Overall, Cs, Rb, and N have higher metallic character compared to Na, Mg, and As respectively.
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In most solutions containing a strong or weak acid, the autoionization of water can be neglected when calculating [H3O+]. Explain why this is so ?
In most solutions containing a strong or weak acid, the autoionization of water can be neglected when calculating [H3O+].
The reason for this is related to the relative concentrations of H3O+ ions produced by the acid and the autoionization process of water.
When an acid is added to water, it donates a proton (H+) to the water molecules, which form hydronium ions (H3O+). In the case of a strong acid,
the dissociation is nearly complete, leading to a high concentration of H3O+ ions. For weak acids, the dissociation is partial, but it still contributes a significant amount of H3O+ ions to the solution.
On the other hand, the autoionization of water is a self-ionization process where two water molecules interact, with one donating a proton to the other,
forming a hydronium ion (H3O+) and a hydroxide ion (OH-). However, the equilibrium constant for this process, Kw, is
very small (approximately 1.0 x 10^-14 at 25°C), which means that the concentration of H3O+ ions produced by water's autoionization is extremely low.
Since the concentration of H3O+ ions contributed by the acid is much greater than that produced by the autoionization of water,
it is reasonable to neglect the autoionization of water when calculating [H3O+]. This simplifies the calculations and provides an accurate enough estimation of the hydronium ion concentration in most acid solutions.
In summary, the autoionization of water can be neglected when calculating [H3O+] in solutions containing strong or weak acids due to the significantly higher concentration of H3O+ ions contributed by the acid.
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What is the substitution of each epoxide carbon in the reactant used? Select one: a. primary b. quaternary c. tertiary d. secondary W.
The question is asking to determine the substitution of each epoxide carbon in the reactant used. Specifically, it is asking whether the carbons are primary, secondary, tertiary, or quaternary.
The substitution of a carbon is determined by the number of alkyl (or aryl) groups bonded to it.
Primary carbons are bonded to one other carbon.Secondary carbons are bonded to two other carbons.Tertiary carbons are bonded to three other carbons.Quaternary carbons are bonded to four other carbons.Therefore, to determine the substitution of each epoxide carbon in the reactant used, we need to know what groups are attached to those carbons. The information provided is not sufficient to answer the question.
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calculate the simplest or empirical formula of a substance with 0.62400 grams of chromium (cr) and 1.42128 grams of selenium (se)(2 points) (2 points) use cr = 52.00 g/mole and se = 78.96 g/mole
The empirical formula of the substance with 0.62400 grams of chromium and 1.42128 grams of selenium is Cr2Se3.
To calculate the empirical formula, we need to determine the mole ratio of the elements in the substance. To do this, we first convert the given masses of chromium and selenium to moles using their respective molar masses.
Moles of chromium = 0.62400 g / 52.00 g/mole = 0.012 mols
Moles of selenium = 1.42128 g / 78.96 g/mole = 0.018 mols
Next, we divide the mole quantities by the smallest of the two values. In this case, chromium has the smallest value of 0.012 moles. So, we divide both values by 0.012.
Moles of chromium (Cr) = 0.012 / 0.012 = 1
Moles of selenium (Se) = 0.018 / 0.012 = 1.5
Now we have the mole ratio of the elements, and we need to convert them to whole numbers by multiplying by a common factor. In this case, the common factor is 2.
Moles of Cr = 1 x 2 = 2
Moles of Se = 1.5 x 2 = 3
Finally, we write the empirical formula using the whole number mole ratios as subscripts. The empirical formula is Cr2Se3.
In conclusion, the empirical formula of the substance with 0.62400 grams of chromium and 1.42128 grams of selenium is Cr2Se3. This formula represents the smallest whole-number ratio of atoms in the substance, based on the given masses and molar masses of the elements. The calculation involves converting the masses to moles, finding the mole ratio, and multiplying by a common factor to obtain the empirical formula.
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A 0.25 mol sample of hbr is added to a 1.00 l buffer solution consisting of 0.68 m hcn (ka = 6.2 * 10-10) and 0.35 m nacn. what is the ph of the resulting solution?
The final pH will be slightly lower than the initial pH of the buffer due to the addition of the HBr. The pH of the resulting solution is 8.25.
The addition of the HBr to the buffer solution will result in the formation of a new weak acid, HCN, and its conjugate base, CN⁻. The addition of HBr will cause a shift in the equilibrium of the HCN dissociation reaction. We can use the Henderson-Hasselbalch equation to calculate the pH of the resulting buffer solution:
pH = pKa + log([CN⁻]/[HCN])
where pKa is the dissociation constant of HCN, and [CN⁻] and [HCN] are the concentrations of CN⁻ and HCN in the buffer solution, respectively.
Substituting the values, we get:
pH = 9.21 +㏒([0.35 - 0.25]/[0.68 + 0.25])
pH = 9.21 + ㏒(0.1/0.93)
pH = 9.21 - 0.96
pH = 8.25
Therefore, the pH of the resulting solution is 8.25.
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which ion of the alkaline earth metals is most likely to undergo hydrolysis
Beryllium (Be2+) is the alkaline earth metal ion most likely to undergo hydrolysis.
How does hydrolysis vary among alkaline earth metal ions?Hydrolysis is a chemical reaction in which a compound reacts with water to form new compounds. Among the alkaline earth metals, the ion that is most likely to undergo hydrolysis is beryllium (Be2+). Beryllium is the lightest alkaline earth metal and has a small ionic radius. Due to its small size, the electron cloud around the beryllium ion is more polarize, meaning it can be easily distorted by external charges.
When beryllium ions come into contact with water molecules, the polarized water molecules can effectively solvable the ions. This salvation process can lead to hydrolysis, where the water molecules break apart the beryllium ions, resulting in the formation of beryllium hydroxide (Be(OH)2) and hydrogen gas (H2). The hydrolysis of beryllium ions is relatively more significant compared to other alkaline earth metals due to the smaller size and higher charge density of beryllium ions.
It's important to note that while beryllium is more prone to hydrolysis among the alkaline earth metals, the reactivity of beryllium with water is still lower compared to alkali metals like sodium or potassium. The hydrolysis of beryllium is a slow process and requires a significant amount of water or an acidic environment to occur at a noticeable rate.
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