CameraIcon

SearchIcon

MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

pH the Power of H

A buffer solu...

Question

A buffer solution of $p H = 4$ is to be prepared, using $C H_{3} C O O H$ and $C H_{3} C O O N a .$ The concentration of acetic acid and sodium acetate are $\frac{1}{10} M$ and $x M$ . How much will the $p H$ be if $1.5 L$ of $H_{2} O$ is added to above buffer ? $K_{a} (C H_{3} C O O H) = 4.7447$

A

4

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

B

6

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

8

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

2

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A $4$
Using the Henderson-Hasselbalch equation for weak acid:
$p H = p K_{a} + l o g \frac{[C H_{3} C O O N a]}{[C H_{3} C O O H]}$
$p H = - l o g K_{a} + l o g \frac{[C H_{3} C O O N a]}{[C H_{3} C O O H]}$
$4 = - l o g 1.8 \times 10^{- 5} + l o g \frac{x}{\frac{1}{10}}$
$4 = 4.7447 + l o g 10 x$
$x = 0.018$ M
If $1.5 L$ of $H_{2} O$ is added it increases the volume, thereby decreasing concentration of both acid and salt. The ratio $l o g \frac{[S a l t]}{[A c i d]}$ remains constant.
So $p H$ remains same that is $p H = 4$

Suggest Corrections

thumbs-up

0

Similar questions

Q. A buffer solution of

p H = 5.74

is to be prepared using

C H_{3} C O O H

C H_{3} C O O N a

. Find the concentration of sodium acetate to be added to

0.01 M

C H_{3} C O O H

K_{a} (C H_{3} C O O H) = 1.8 \times 10^{- 5}

l o g (1.8) = 0.26

Q. A buffer solution of

p H = 5.74

is to be prepared using

C H_{3} C O O H

C H_{3} C O O N a

. Find the concentration of sodium acetate to be added to

0.01 M

C H_{3} C O O H

K_{a} (C H_{3} C O O H) = 1.8 \times 10^{- 5}

l o g (1.8) = 0.26

Q. What will be the new

p H

0.01 m o l

N a O H

1 L

buffer solution that is

0.1 M

(C H_{3} C O O H)

0.1 M

in sodium acetate

(C H_{3} C O O N a)

?
Dissociation constant

K_{a}

of acetic acid at

25^{\circ} C

1.8 \times 10^{- 5}

Q. In order to prepare a buffer solution of pH 5.74, sodium acetate is added to acetic acid. If the concentration of acetic acid in the buffer is 1.0 M, the concentration of sodium acetate in the buffer is ______M. (Round off to the Nearest Integer).
[Given:

p K_{a}

(acetic acid) = 4.74]

Q. Suppose it is required to make a buffer solution of

p H = 4

, using acetic acid and sodium acetate. How much of sodium acetate is to be added to

1

N / 10

acetic acid?
Dissociation constant of acetic acid

1.8 \times 10^{- 5}

View More

Join BYJU'S Learning Program

explore_more_icon

Explore more

pH the Power of H

Standard XII Chemistry

Join BYJU'S Learning Program

CrossIcon