Question

The pH of a solution obtained by mixing 50 mL of 0.2 M HCl with 50 mL of 0.20 M `CH_(3) C O OH` is
A. `0.30`
B. `0.70`
C. `1.00`
D. `2.00`

Answer 1

Correct Answer - C
Acetic acid being a weak acid ionizes to a small extent Its ionization is further suppressed in the presence of HCl. Hence, `H^(+)` ions are obtained mainly from HCl.
50 ml of 0.2 M HCl=`50xx0.2` millimoles
= 10 millimoles
Volume of solution after mixing = 100 mL
`:.` Molar conc.of HCl `=(10)/(100)=0.1M = 10^(-1)M`
`:. pH=1`