Physical Chemistry MCQ with Answers

Physical Chemistry MCQ with Answers

256) 20 mL of 0.1M acetic acid is mixed with 50 mL of potassium acetate. K_a of acetic acid = 1.8 x 10⁻⁵ at 27^oC. Calculate concentration of potassium acetate, if pH of the mixture is 4.8:

Answer is:

0.04M

257) Fear or excitement, generally causes one to breathe rapidly and it results in the decrease of CO₂ concentration in blood. In what way will it change the pH of blood?

Answer is:

No change

Explanation:

Blood itself is a buffer solution, so a small change in CO₂ concentration will not affect its pH.

258) The pH at the equivalence point of a titration may differ from 7 because of:

Answer is:

Hydrolysis of the salt formed

Explanation:

Saly hydrolysis affects the pH of the solution.

259) The hydrogen ion concentration of 0.06M benzoic acid solution will be: (K_a = 6 x 10⁻³)

Answer is:

6 x 10⁻⁴

Explanation:

[H⁺] = Cα

260) A beaker contains 1 L of 0.1M acetic acid solution. To neutralize the acid partially, 1 gm of NaOH has been added. If the pK_a of acetic acid is 4.75, then the pH of the partially neutralized acetic acid solution will be:

Answer is:

4.28

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