Question

0.1 M HCl and 0.1 M `H_(2)SO_(4)`, each of volume 2 ml are mixed and the volume is made up to 6 ml by adding 2 ml of 0.01 N NaCl solution. The pH of the resulting mixture is
A. `1.17`
B. `1.0`
C. `0.3`
D. log 2 - log 3

Answer 1

Correct Answer - B
2 ml of 0.1 M HCl = 0.2 millimole of HCl
= 0.2 millimole of `H^(+)` ion
2 ml of 0.1 M `H_(2)SO_(4)= 0 .2` millimole of `H_(2)SO_(4)`
= 0.4 millimole of `H^(+)` ion
Total `H^(+)` ions = 0.6 millimole
Total volume = 6 ml
`:. [H^(+)]=(0.6)/(6)M=0.1 M = 10^(-1)M :. pH = 1`.