Neco 2019 Chemistry Question 39

Practice objective / multiple choice question 39 from the 2019 Neco Chemistry examination.

Neco 2019 Chemistry Objective / Multiple Choice Medium Difficulty
Question 39 NECO • 2019 • CHEMISTRY • objective

A buffer is prepared by dissolving 0.250 mol of acetic acid (\(\mathrm{CH_{3}COOH}\), \(K_{a}=1.8\times10^{-5}\)) and 0.150 mol of sodium acetate in 1.00 L of water. (a) Calculate the initial pH of the buffer. (b) After adding 0.050 mol of NaOH, what is the new pH? (c) How many millilitres of 0.100 M HCl are required to restore the original pH? (Assume volumes are additive.)

Answer Options

A. Initial pH = 4.45; after NaOH addition pH = 4.70; HCl required = 600 mL
Correct Answer B. Initial pH = 4.52; after NaOH addition pH = 4.74; HCl required = 500 mL
C. Initial pH = 4.30; after NaOH addition pH = 4.55; HCl required = 450 mL
D. Initial pH = 4.60; after NaOH addition pH = 4.80; HCl required = 550 mL
Correct Answer
B
Correct Option:
Initial pH = 4.52; after NaOH addition pH = 4.74; HCl required = 500 mL

About This Question

This is Neco 2019 Chemistry Question 39. It is one of the objective questions from the 2019 Neco Chemistry examination.

Difficulty level: Medium .

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