Question

A 1.00 liter solution contains 0.35M acetic acid and 0.26 M potassium acetate. If 35.0 mL of water are added to this system, indicate whether the following statements are true or false. (Note the the volume MUST CHANGE upon the addition of water) A. The concentration of CH3COOH will decrease. True False B. The concentration of CH3COO" will remain the same C. The equilibrium concentration of H30* will increase D. The pH will increase E. The ratio of [CH3COOH]/ [CH3coo] will increase. 9 more group attempts remaining Submit Answer Retry Entire Group

Answer 1

Part A

Concentration of acetic acid

= [moles of acetic acid /volume of solution (L)]

So, if volume is increased therefore the concentration of CH₃COOH decreases (true).

and concentration of acetate ion alse decreases , hence their ratio will be same.

pH = pKa + log[CH₃COO^-]/[CH₃COOH]

Hence,

Other statements are false.

Part B

If 0.300 mole NaOH is added then it reacts with hypochlorous acid to give hypochlorite ion .

NaOH + HClO $\to$ NaClO + H₂O

Hence, the number of moles of HClO will decrease (true).

The number of moles of ClO^- will increase (true) .

Equilibrium concentration of H₃O⁺ remain the same (false) .

pH will decrease ( false).

The ratio of [HClO] /[ClO^-] will decrease (false).