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

Lewis Theory

A weak base ...

Question

A weak base $B O H$ is titrated with a strong acid $H A$ . When $10 m l$ of $H A$ is added, $p H$ is found to be $9.00$ and when $25 m l$ is added, $p H$ is $8.00$ . The volume of the acid required to reach the equivalence point is

35 m L

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

40 m L

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

30 m L

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

50 m L

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

Open in App

Solution

The correct option is B $30 m L$
$B O H$ $+$ $H A$ (buffer)
weak strong
$P H = 14 - {P K}_{b} - l o g \frac{[B^{+}]}{[B O H]}$
$x$ millimoles of base
$y$ be concentration of acid
$9 = 14 - {P K}_{b} - l o g \frac{10 \times y}{x - 10 y} \to (1)$
$8 = 14 - {P K}_{b} - l o g \frac{25 y}{x - 25 y} \to (2)$
$(1)$ $-$ $(2)$
$1 = l o g (\frac{25 y}{x - 25 y} \times \frac{x - 10 y}{10 y})$
$10 = (\frac{25}{10}) \frac{x - 10 y}{x - 25 y}$
$4 = \frac{x - 10 y}{x - 25 y}$
$4 x - 100 y = x - 10 y$
$3 x = 90 y$
$x = 30 y$
$30 y \Rightarrow$ $30 m l$ of acid with $y$ molarity.

Suggest Corrections

Similar questions

Q. A solution of weak acid

H A

was titrated with base

N a O H

. The equivalence point was reached when

36.12 m L

0.1 M

N a O H

has been added. Now

18.06 m L

0.1 M

H C l

were added to titrated solution, the

p H

was found to be

4.92

. What will be the

p H

of the solution obtained by mixing

10 m L

0.2 M

N a O H

and

10 m L

0.2 M

H A

Q. A weak base

B O H

was titrated against a strong acid. The

p H

\frac{1}{4}

th equivalence point was

9.24

. Enough strong base was now added (

6

meq.) to completely convert the salt. The total volume was

50 m L

. Find the

p H

at this point.

Q. A solution of weak acid was titrated with base

N a O H

. The equivalence point was reached when

36.12 m L

0.1 M N a O H

have been added. Now

18.06 m L 0.1 M H C l

were added to titrated solution, the

p H

was found to be

4.92

. What is

K_{a}

of acid?

Q. A weak acid

(50.0 m L)

was titrated with

0.1 M

N a O H

. The

p H

values when

10.0 m L

and

25.0 m L

of base have been added are found to be

4.16

and

4.76

respectively. Calculate

K_{a}

of the acid and

p H

at the equivalence point.

Q. A strong acid is titrated with weak base. At equivalence point, pH will be

Join BYJU'S Learning Program

A weak base BOH is titrated with a strong acid HA. When 10 ml of HA is added, pH is found to be 9.00 and when 25 ml is added, pH is 8.00. The volume of the acid required to reach the equivalence point is

A weak base $B O H$ is titrated with a strong acid $H A$ . When $10 m l$ of $H A$ is added, $p H$ is found to be $9.00$ and when $25 m l$ is added, $p H$ is $8.00$ . The volume of the acid required to reach the equivalence point is