What is the change in pH when 10.0 mL of 0.250 M KOH (aq) is added to 100.0 mL of a buffer that is 0.150 M in HCOOH (aq) and 0.100 M in HCOO^– (aq)? pK_a = 3.75 for HCOOH (aq).

Select one:

a. –0.26 pH unit

b. +0.18 pH unit

c. +0.00 pH unit

d. –0.81 pH unit

QUESTION 2

What is the molarity of an aqueous barium hydroxide solution if it takes 59.9 mL of 0.100 M HCl (aq) to neutralize 21.6 mL of the Ba(OH)₂ (aq) solution?

Select one:

a. 0.208 M

b. 0.277 M

c. 0.139 M

d. 0.0693 M

Given a solution of 0.125 M CH₃COOH (aq) and a solution of 0.150 M NaCH₃COO (aq), how would you prepare 100.0 mL of a buffer solution with a pH of 4.400? pK_a = 4.740 for CH₃COOH (aq).

Select one:

a. Mix 68.6 mL of the CH₃COOH (aq) with 31.4 mL of the NaCH₃COO (aq)

b. Mix 27.6 mL of the CH₃COOH (aq) with 72.4 mL of the NaCH₃COO (aq)

c. Mix 72.4 mL of the CH₃COOH (aq) with 27.6 mL of the NaCH₃COO (aq)

d. Mix 50.0 mL of the CH₃COOH (aq) with 50.0 mL of the NaCH₃COO (aq)

QUESTION 2

If 15.9 grams of NH₄Cl (s) are added to 250.0 mL of 0.350 M NH₃ (aq) solution, what is the resulting pH? Assume no change in volume upon adding the NH₄Cl (s). pK_a = 9.25 for NH₃ (aq).

Select one:

a. 8.55

b. 8.38

c. 9.06

d. 8.72

A mixture is made by combining 11.5 mL of 8.5×10−3 M KSCN, 6.3 mL of 3.7×10−2 M Fe(NO3)3, and 10.4 mL of 0.397 M HNO3. Calculate the concentraion of Fe3+ in the solution.

1. Assume that the rate law for a reaction is rate = k[A][B]^2

a) what is the overall order of the reaction?

b) if the concentration of both A and B are doubled, how will this affect the rate of the reaction?

c) how will doubling the concentration of A, while the concentration of B is kept constant, affect the value of k (assume that temperature does not change)? how is the rate affected?

2. It is found for the reaction 2A + B ---> C that doubling the concentration of either A or B while maintaining the other concentration constant quadruples the reaction rate. Write a rate law for the reaction.

Given the E⁰ values of the following two half-reactions:

Zn à Zn²⁺ + 2e^-               E⁰ = 0.763 volt

Fe à Fe²⁺ + 2e^-                E⁰ = 0.441 volt

a)Write a balanced complete oxidation-reduction reaction?

b)Explain whether the corrosion of an iron pipe (i.e., Fe Fe²⁺) in the presence of Zn/Zn²⁺ is possible or not (thermodynamically)?

c)Explain whether or not Zn will protect the corrosion of iron pipe if metallic Zn is in contact with the iron pipe?

In a experiment, 1 ml of .01 M KMnO4 plus 6 drops of 6 M H2SO4 are added together with drops of 0.1 M FeSO4 until change occurs. The color changed from purple to a clear solution. What is the oxidizing agent and reducing agent ? The balanced net ionic equation with 1/2 reactions? Thank you.

Based on material science and diffusion, how is beef marinated? This question was given by my professor as a way to apply diffusion to the real world and if you can give me a basic understanding that would be awesome. Thank you.

Given the following pairs of half-reactions, please construct a complete balanced oxidation-reduction reaction for each pair of two half-reactions:

a) H₂= 2H⁺ + 2e^-

Fe²⁺= à Fe³⁺ + e^-

b) 1/4O₂(g) + H⁺+ e- == ½ H₂OH₂ =à 2H⁺+ 2e^-

   ^C) 2IO₃^-+ 12H⁺+ 10e^-== I₂+ 6H₂O 2I^-= I₂+ 2e^-

Calculate the change in pH to 0.01 pH units caused by adding 10. mL of 3.69-M NaOH is added to 530. mL of each of the following solutions.

a.) water

pH before mixing: 7.00 (correct)

pH after mixing: ??

b.) 0.180 M NH₃

pH before mixing: 11.26

pH after mixing: ??

Thank you! Sincerely, a confused college student

State the dominant intermolecular forces for the following substances:

iron(III)chloride

phosphorous trichloride

boron trichloride

BeH₂

H₂O

XeF₂

PH₃

CrCl₃

SF₂

CS₂

Calculate the pH of each of the solutions and the change in pH to 0.01 pH units caused by adding 10.0 mL of 3.63-M HCl to 440. mL of each of the following solutions.

a.) .181 M C2H3O2 1-

ph before mixing: 9.00 (correct)

pH after mixing: ??

b.) a buffer solution that is 0.181 M in each C2H3O2 1- and HC2H3O2

pH before mixing: ??

pH after mixing: ??

Thank you!! Sincerely, a confused college student

A mixture of carbon dioxide and nitrogen gases, in a 7.69 L flask at 36 °C, contains 10.4 grams of carbon dioxide and 7.77 grams of nitrogen. The partial pressure ofnitrogen in the flask is (?) atm and the total pressure in the flask is (?) atm

thanks in advance

You have 200 ml of 0.1M HEPES buffer, pH 7.5. You add 2 ml of 0.4M HCl. The pKa of HEPES is 7.5.

a) what will the resulting pH be?

b) what would the pH be if no HEPES were present (that is, you mixed water and HCl)?

Determine the pH at the equivalence point when 0.05 M KOH is titrated with 50.0 ml of 0.01 M benzoic acid HC₇H₅O₂. The K_a for benzoic acid is 6.3 x10^-5.

Physical Chemistry problem:

How does the confinement of a particle to a finite region of space lead to the quantization of its energy? You may use any combination of words, images, or equations to support your answer.