Question

Tu pH of a mixture of equal volumes of 0.2 M HCL and 0.2 M CH3COOH is____.
(a)2.0
(b)3.4
(c)4.7
(d)5.0​

Answer 1

Answer:

Whem equal volume volume of 0.02HHOCl and 0.2MCH

3

COOH are mixed.

New conc. of HOCl=

2

0.02

=0.01H

New conc of CH

3

COOH=

2

0.2

=0.1H

Now,

For a mixture of weak acids we know

[H

+

]=

Ka

1

C

2

+Ka

2

C

2

=

2×10

−4

×10

−2

+2×10

−5

×10

−1

=

4×10

−6

=2×10

−3

∴ph=3−log

2

=2.7