Question

To find volume of water, which should be added to 11 of a 0,6 % solution of an acetic acid (p = 1) for reception of a solution with pH =3 (Kd = 1,8 10).

Answer 1

The concentration of the solution is unknown.

The pH of the solution is $3.00$

The new volume is unknown.

The equilibrium equation is;

$CH_3COOH\leftrightharpoons H^++CH_3COO^-$ At equilibrium, $C_o=1.8\times 10^-5$

$K_d=$$[H^+][CH_3COO^-]\over[CH_3COOH]$

$=$ $[1.8\times 10^{-5}]\times[1.8\times 10^{-5}]\over [-1.8\times 10^{-5}]$ $=3.6\times 10^{-5}$

$[H^+]=10^{-3.00}$

The volume in litres of the solution is;

$V=$ $1\over 3.6\times 10^{-5}$ $=2.7\times 10^4$ $L$

T

$0.6\over 100$ $\times 2.7\times 10^4=1.6\times 10^2L$

The new volume $=$ $1.6\times 10^2 L$