Answer:
2.4g of NaClO must be added
Explanation:
To find the pH of a buffer we must use H-H equation:
pH = pKa + log [A⁻] / [HA]
Where pH is the pH of the buffer, 7.35
pKa of the HClO buffer is 7.54
[A⁻] could be taken as moles of NaClO
And [HA] moles of the weak acid: 500mL = 0.500L * (0.1mol/L) = 0.05 moles
Replacing:
pH = pKa + log [A⁻] / [HA]
7.35 = 7.54 + log [A⁻] / [0.05moles]
0.6457 = [A⁻] / [0.05moles]
0.03228 moles = Moles of NaClO we need to make the pH = 7.35 buffer.
To convert these moles to grams we use the molar mass of NaClO (74.44g/mol):
0.03228 moles * (74.44g/mol) =
2.4g of NaClO must be added
what is 19.0 ul in ml
____ KClO3 = ____ KCl + ____ O2
Answer:
2KCIO3=2KCI+3O2
Explanation:
1. equalize right side O with left side O- Right side we have 3 and left only 2 so we add 3 in front(on left side)(3*2=6 O on both sides)
2.we add 2 on right side so now we have 6 O on left and 6 O on right and 2KCI
3.Add 2 on right side KCI so on both sides we got 2 KCI
32. A chemical reaction in which calcium carbonate CaCO3 is decomposed, results in the
production of two simpler compounds.
CaCO3
>CaO
+
CO2
? 9
28.00 g
21.97 g
What mass of calcium carbonate, to the nearest hundredth of a gram, is
decomposed in this reaction?
Answer:
Mass of calcium carbonate decompose 49g.
Explanation:
Given data:
Mass of CaO = 28.00 g
Mass of CO₂ = 21.97 g
Mass of calcium carbonate decompose = ?
Solution:
Chemical equation:
CaCO₃ → CO₂ + CaO
Number of moles of CO₂:
Number of moles = mass/molar mass
Number of moles = 21.97 g / 44 g/mol
Number of moles = 0.49 mol
Number of moles of CaO:
Number of moles = mass/molar mass
Number of moles = 28.00 g / 56.1 g/mol
Number of moles = 0.49 mol
Now we will compare the moles of CaCO₃ with CaO and CO₂ .
CO₂ : CaCO₃
1 : 1
0.49 : 0.49
CaO : CaCO₃
1 : 1
0.49 : 0.49
Mass of CaCO₃ decompose:
Mass = number of moles × molaer mass
Mass = 0.49 mol × 100.1 g/mol
Mass = 49 g
Answer:
CaO
Explanation:
Move the chemistry book down again so it's surface touches the physics book. Quickly move the chemistry book back and forth. What's different when motion is faster?
Answer:
The temperature of the physics book increases as the chemistry book slides across it.
Explanation:
from plato
The temperature of the physics book increasing as the chemistry book slides across it is the difference when motion is faster.
What is Temperature?This is defined as the degree of hotness or coldness of a body and it increases when there is more friction.
When motion is faster , there is an increase in friction and increase in thermal(heat) energy which leads to increase in temperature.
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"Calculate the pH of an aqueous solution at 25°C that is (a) 0.15 M in HCl. 0.82 (b) 3.7 M in HNO3. -0.57 (c) 6.9 × 10−4 M in HClO4."
Answer:
See explanation
Explanation:
The pH of a solution is defined as the negative logarithm of hydrogen ion concentration.
For HCl
pH= - log[0.15] = 0.82
For HNO3
pH= -log[3.7] = -0.57
For HClO4
pH= - log [6.9 × 10^-4] = 3.16
the density of an 18.0 solution of ammonium sulfate is 1.10g/ml. What mass of Ammonium sulfate is required to prepare 275ml of this solution
Answer:
Therefore, 54.45 g of Ammonium sulphate is required
Explanation:
Molar mass of ammonium sulphate, (NH₄)₂SO₄ = 132 g/mol
Since density of solution is 1.10 g/ml, a 1 mL solution has mass = 1.10 g
275 mL solution will have a mass = 275 * 1.10 = 302.5 g
Since the solution is 18% ammonium sulphate by weight,
mass of ammonium sulphate present in 275 mL solution = 302.5 * 18/100
mass of ammonium sulphate present in 275 mL solution = 54.45 g
Therefore, 54.45 g of Ammonium sulphate is required
PLZ HELP ME...
Graceful, and yet majestic, it clings to the land like a thing that has taken root. Beautiful as a vision of fairyland it salutes our sight. The impression it makes upon the visitor is one of astonishment, an astonishment that grows with every visit. No one who has been upon it can ever forget it. This great structure cannot be confined to the limits of local pride. The glory of it belongs to the race. Not one shall see it and not feel prouder to be a man.
Which of the following is the best objective summary of the excerpt?
The Brooklyn Bridge is an unforgettable sight!
The glory of the bridge belongs to the human race.
The grandeur of the bridge would make people feel proud.
Visitors of New York should be astonished by the bridge.Is a compound considered a pure substance? Why or why not?
BTW im on edguinity
Answer:
its b
Explanation:
its b sorry if im wrong but mine said b
Answer:
B.
Explanation: I got it right on edg
Concentration data is commonly monitored during a reaction to determine the order with respect to a reactant. Consider the types of observations listed, and determine which order is likely for that reactant. Assume all other factors are held constant.
1. An increase in the concentration of the reactant in solution causes the reaction rate to increase exponentially.
a. first order
b. second order
c. zero order
2. The reaction rate increases in direct proportion to the concentration of the reactant in solution.
a. first order
b. second order
c. zero order
3. The reaction rate is constant regardless of the amount of reactant in solution.
a. first order
b. second order
c. zero order
Answer:
1) first order
2) second order
3) zero order
Explanation:
The curve of a first order reaction shows it to be exponential. In fact for a first order reaction, the concentration at a time t is an exponential function;
[A]t= [Ao] e^-kt
Where
[A]t = concentration at time =t
[Ao]= initial concentration
k= rate constant
t= time
For a second order reaction, the rate of reaction is directly proportional to the concentration of reactants.
For zero order reactions, rate of reaction is independent of concentration hence rate = k(rate constant)
The concentration data has been required for the determination of the rate of reaction. Based on the concentration of reactant and product, the rate has been determined.
1. For the first-order reaction, there has been an exponential increase in the rate of the reaction with the increase in the reactant concentration. The rate has been dependent on the concentration of the reactant.
Thus the correct option is A.
2. Irrespective of the first-order kinetic, in the second-order reaction, the rate of reaction has been directly proportional to the concentration of the reactant in the solution.
Thus option B is correct.
3. The zero-order reaction has been independent of the concentration of the reactant. The rate of reaction has been constant with an increase in the reactant concentration.
Thus option C is correct.
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calculate the amount of water produced by the combustion of 16 gram of methane
Answer: Since, the given weight of methane is 16 g, hence the water produced by the combustion of 16 g of methane is 36 g.
Explanation: Have a blessed day!
Which is true of both the rock cycle and the water cycle?
both occur mostly in the atmosphere
both occur mostly in the geosphere
both have no beginning and no end
matter is created by both of them
A
Because both occur mostly in the atmosphere
And If both happens in the atmosphere it makes it the only answer by default
The study of the rocks is called petrology.
The correct answer to the question is option B that is both occur mostly in the geosphere.
What is a geochemical cycle?A geochemical cycle is the pathway that chemical elements take in the surface and crust of the Earth. The term geochemical tells us that geological and chemical factors are all included.
According to the question, both water and the rocks are present on the land and go to the reservoir with the help of a process called leaching. The common passage for both the cycling island.
Hence, the correct answer is option B.
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What is the volume of 4.62 g of mercury? The density of mercury is 13.5 g/cm3.
Answer:
The answer is 0.342 cm³Explanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
From the question
mass = 4.62 g
density = 13.5 g/cm³
We have
[tex]volume = \frac{4.62}{13.5} \\ = 0.3422222...[/tex]
We have the final answer as
0.342 cm³Hope this helps you
There are approximately 250 million passenger vehicles in the United States. If each is driven 25,000 km per year, calculate the total mass of CO, NOx and HC emitted in 1970 if all vehicles just meet the government standard at that time. Please find the standard values in textbook. (Please round up to 3 decimal points and use 'E' for exponent)
Answer:
CO = 1.320 x 10¹¹ Kg
NOx = 1.942 x 10¹⁰ Kg
HC = 1.592 x 10¹⁰ Kg
Explanation:
Given that;
there are approximately 250 million passenger vehicles
each is driven 25,000 km per year which is 15534.28 miles per year
In 1970, the vehicular emission norms are;
CO = 34 g/mile , NOx = 5 g/mile , HC = 4.1 g/mile
so emission of CO in 1970 is;
250000000 × 15534.28 × 34 g
= 1.320 x 10¹⁴ g
= 1.320 x 10¹¹ Kg
Also, emission of NOx in 1970
250000000 × 15534.28 × 5 g
= 1.9417 x 10¹³ g
= 1.942 x 10¹⁰ Kg
emission of HC in 1970
= 250000000 × 15534.28 × 4.1 g
= 1.5922 x 10¹³ g
= 1.592 x 10¹⁰ Kg
Which of the following best support the function of electrical signals in the nervous system?
Each nerve cell is connected to the brain by electrical signals.
Nerve cells communicate with the brain by sending out electrical signals
Electrical signals keep nerve cells alive.
Electrical signals are used to get rid of waste produced in the nervous system.
Answer:
Each nerve cell is connected to the brain by electrical signals
Explanation:
Answer:
they said it above me
Explanation:
I need help with 5 and 6
Finally, someone gave a clear photo.
What can the chemical formula tell us about a compound?
Answer:
A chemical formula tells us the number of atoms of each element that is in a compound. It contains the symbols of the atoms for the elements present in the compound as well as how many there are for each element in the form of subscripts.
Hope this helps! please mark me brainliest!
God bless :)
How does ionic bond forms?
Answer:
Ionic bond, also called electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when the valence (outermost) electrons of one atom are transferred permanently to another atom.
Explanation: i took the same test
Answer:
it forms where a metal element and a non metal element react together to form a now compound
Can someone help me with this chemistry I have attached?, just helping me understand these problems. Its moles and questions
the kind of bond present in CUSO4.5H20
Answer:
Both ionic bonds and covalent bonds (coordinate and non-coordinate) are present in crystalline [tex]\rm CuSO_4\cdot 5\, H_2O[/tex].
Explanation:
[tex]\rm CuSO_4\cdot 5\, H_2O[/tex] can be formed by adding water to the anhydrous salt [tex]\rm CuSO_4[/tex].
[tex]\rm CuSO_4[/tex] itself is an ionic compound consisting of [tex]\rm Cu^{2+}[/tex] ions and [tex]\rm {SO_4}^{2-}[/tex] ions. Ionic bonds are present between these ions. However, within each sulfate [tex]\rm {SO_4}^{2-}[/tex] ion, covalent bonds connect the central sulfur atom to each of the oxygen atoms.
Water molecules [tex]\rm H_2O[/tex] are highly polar. Partial negative charges surround the oxygen atom in each water molecule.
When water is added to anhydrous [tex]\rm CuSO_4[/tex], the negatively-charged portion of these [tex]\rm H_2O\![/tex] molecules would be attracted to the positively-charged [tex]\rm Cu^{2+}[/tex] ions in [tex]\rm CuSO_4\![/tex].
Lone pairs on oxygen atoms in [tex]\rm H_2O\!\![/tex] would form coordinate covalent bonds with [tex]\rm Cu^{2+}\![/tex] ions. (These bonds are considered "coordinate" because both electrons in each of these bonds come from the oxygen atom, not the [tex]\rm Cu^{2+}[/tex] ion.) That would produce coordination complexes with one [tex]\rm Cu^{2+}\!\![/tex] ion and five [tex]\rm H_2O\!\!\![/tex] "ligands" each.
Because the [tex]\rm H_2O[/tex] ligands carry no electric charge, each of these complexes would also carry a charge of [tex](+2)[/tex] (same as the charge on one [tex]\rm Cu^{2+}\!\![/tex] ion.) Ionic bonds would be present between the positively-charged coordination complexes and the negatively-charged [tex]\rm {SO_4}^{2-}[/tex] ions.
Summary:
Covalent bonds are present within [tex]\rm {SO_4}^{2-}[/tex] ions and [tex]\rm H_2O[/tex] ligands.Coordinate covalent bonds are present between [tex]\rm H_2O[/tex] ligands and [tex]\rm Cu^{2+}[/tex] ions.Ionic bonds are present between [tex]\rm {[Cu\, (H_2O)_5]}^{2+}[/tex] coordination complexes and sulfate ions [tex]\rm {SO_4}^{2-}[/tex].Which element is classified as a noble gas?
Answer:
any of the seven chemical elements that make up Group 18 (VIIIa) of the periodic table. The elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og). :)
Explanation:
Answer:
For edge, the answer is;
D. Xe
(Xenon)
Explanation:
edg- answers ;p
atmospheric pressure at elevations of 8000 feet averages about 0.72 atmospheres. Would a cabin pressurized at 500 mm hg meet federal standards
Answer:
Yes, but it must be kept at that value and do not let it to decrease more.
Explanation:
Hello.
In this case, in order to substantiate whether the cabin meet the federal standards, we need to convert the 500 mmHg to atm and compare the result with 0.72 atm by knowing that 1 atm equals 760 mmHg:
[tex]500mmHg*\frac{1atm}{760mmHg} \\\\=0.66atm[/tex]
Thus, since 0.66 atm is 0.06 atm away from the federal standard we can infer that it may meet the federal standard, however, it would not be recommended to let the pressure decrease more than that.
Yes, the cabin pressurized at 500 mm hg meets federal standards.
1 atm is approximately equal to 760 mm Hg. Therefore, the pressure is:
500 mm Hg / 760 mm Hg/atm ≈ 0.65789 atm
So, the cabin pressure of 500 mm Hg is approximately 0.65789 atmospheres. If the atmospheric pressure at an elevation of 8000 feet averages about 0.72 atmospheres, then the cabin pressure of 0.65789 atmospheres would be lower than the ambient atmospheric pressure.
To meet federal standards, cabin pressure should be maintained at an equivalent pressure that allows occupants to breathe comfortably.
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The initial pressure of a mixture of C6H6 and an excess of H2 in a rigid vessel is 1.21 atm. A catalyst is introduced. After the reaction reaches completion, the temperature is restored to its initial value. The final pressure in the vessel is 0.839 atm. What was the mole fraction of C6H6 in the original mixture
Answer:
mole fraction of C6H6 = 0.613 atm
Explanation:
The equation for this reaction is :
[tex]C_6H_6 _{(g)} + 3H_2_{(g)} \to C_6H_{12}_{(g)}[/tex]
Initial P₁ P₂ 0
Final 0 P₂ -P₁/2 P₁
After completion of the reaction;
P₁ + P₂ = 1.21 atm ----- (1)
P₂ - P₁/2 + P₁ = 0.839 atm
P₂ + P₁/2 = 0.839 atm ----- (2)
Subtracting (2) from (1); we have:
P₁/2 = 0.371
P₁ = 0.742 atm
From(1)
P₁ + P₂ = 1.21 atm
0.742 atm + P₂ = 1.21 atm
P₂ = 1.21 atm - 0.742 atm
P₂ = 0.468 atm
Thus, the partial pressure of C6H6 = 0.742 atm
∴
Partial pressure = Total pressure × mole fraction of C6H6
mole fraction of C6H6 = Partial pressure / Total pressure
mole fraction of C6H6 = 0.742 atm / 1.21 atm
mole fraction of C6H6 = 0.613 atm
The data table shows the number of pumpkin seeds that germinate at different temperatures. What is the median number of seeds that germinate at 24C?
A. 80.5 B. 82 C. 78.5 D. 80
Answer:
Explanation:
80
Particle motion in ice is __________than partlice motion in water.
1. faster
2. slower
3. the same
Answer:
1. Faster
Explanation:
Does the Bohr model work for atoms other than hydrogen?
Answer:
The "Bohr Model", works only for hydrogen because it considers only the "interactions" between one electron and the nucleus.
Explanation:
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What is another term for the limbic system?:
A. primitive brain
B. logical brain
C. gender center
D. memory center
Answer:
a
Explanation:
because the sytem it si locate at the bothe side
Explain how plucking occurs
Answer:
plucking is usually extracting hair
Explanation:
example: pluck the chicken feathers
pluck my brows
A solution with a Ph of 13 would be classified as a_____
strong base
strong acid
weak acid
weak base
Answer:
strong base
Explanation:
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a water sample is found to have a cl- content of 100ppm as nacl what is the concentration of chloride in moles per liter
Answer:
The concentration of chloride ion is [tex]2.82\times10^{-3}\;mol/L[/tex]
Explanation:
We know that 1 ppm is equal to 1 mg/L.
So, the [tex]Cl^-[/tex] content 100 ppm suggests the presence of 100 mg of [tex]Cl^-[/tex] in 1 L of solution.
The molar mass of [tex]Cl^-[/tex] is equal to the molar mass of Cl atom as the mass of the excess electron in [tex]Cl^-[/tex] is negligible as compared to the mass of Cl atom.
So, the molar mass of [tex]Cl^-[/tex] is 35.453 g/mol.
Number of moles = (Mass)/(Molar mass)
Hence, the number of moles (N) of [tex]Cl^-[/tex] present in 100 mg (0.100 g) of [tex]Cl^-[/tex] is calculated as shown below:
[tex]N=\frac{0.100\;g}{35.453\;g/mol}=2.82\times 10^{-3}\;mol[/tex]
So, there is [tex]2.82\times10^{-3}\;mol[/tex] of [tex]Cl^-[/tex] present in 1 L of solution.
Express the following numbers in scientific notation:
872
Answer:
The number 872 would be written as,
8.72× 10²
Explanation:
Scientific notation is used to express the large value in short form.
The number in scientific notation have two parts.
First part:
The digits (decimal point will place after first digit)
Second part:
× 10 ( the power which put the decimal point where it should be)
For example the number 872 would be written as
8.72× 10²
Another example:
6324.4 in scientific notation will be written as = 6.3244 × 10³
why ice melt into water