Ostwald Dilution Law Mathematical Interpretation

Q.

Aqueous solution of $HCl$ has the pH = 4. Its molarity would be

1. 0.0001 M

2. 10 M

3. 0.4 M

4. 4 M

Q.

The dissociation constant of two acids $H{A}_1$ and $H{A}_2$ are $3.14\times {10}^{-4}$ and $1.96\times {10}^{-5}$ respectively. The relative strength of the acids will be approximately

1. 1:4

2. 4:1

3. 1:16

4. 16:1

Q.

Nicotinic acid (Ka = 1.4 x ${10}^{-5}$) is represented by the formula HNic. For a solution which contains 0.10 mol of nicotinic acid per 2.0 litre of solution, the percent dissociation is:

1. 4.2%

2. 12.77%

3. 1.66%

4. 3.33%

Q. Accumulation of lactic acid $\left(H{C}_3{H}_5{O}_3\right),$ a monobasic acid in tissues leads to pain and a feeling of fatigue. In a 0.10 M aqueous solution, lactic acid is 3.7% dissociates. The value of dissociation constant, $K_a,$ for this acid will be

1. $1.4\times {10}^{-5}$
2. $1.4\times {10}^{-4}$
3. $3.7\times {10}^{-4}$
4. $2.8\times {10}^{-4}$

Q.

What is the conc. of acetic acid that must be added to 0.5M HCOOH solution so that the dissociation of both acids is the same? [An example of Isohydric solutions] $K_a$ of acetic acid $1.8\times {10}^{-5},K_a$ of formic acid = $2.4\times {10}^{-4}$

1. 4.5 M

2. 3.2 M

3. 6.66 M

4. 12.3 M

Q. Accumulation of lactic acid $\left(H{C}_3{H}_5{O}_3\right),$ a monobasic acid in tissues leads to pain and a feeling of fatigue. In a 0.10 M aqueous solution, lactic acid is 3.7% dissociates. The value of dissociation constant, $K_a,$ for this acid will be

1. $1.4\times {10}^{-5}$
2. $1.4\times {10}^{-4}$
3. $3.7\times {10}^{-4}$
4. $2.8\times {10}^{-4}$

Q. 0.2 M solution of formic acid is ionized 3.2$\%$, its ionization constant is

1. $9.6\times {10}^{-3}$
2. $2.1\times {10}^{-4}$
3. $1.25\times {10}^{-6}$
4. $4.8\times {10}^{-5}$

Q.

What is the conc. of acetic acid that must be added to 0.5M HCOOH solution so that the dissociation of both acids is the same? [An example of Isohydric solutions] $K_a$ of acetic acid $1.8\times {10}^{-5},K_a$ of formic acid = $2.4\times {10}^{-4}$

1. 4.5 M

2. 3.2 M

3. 6.66 M

4. 12.3 M

Q. Which of the following has the same pH as 1 L of a 0.1 M $C{H}_{3}COOH$ solution?
$K_a=1.8\times {10}^{-5}$ for $C{H}_{3}COOH$
Take $(1.34{)}^2=1.8$

1. $3mMHCOOH(K_a=6\times {10}^{-4})$
2. $0.1MC{H}_{3}COONa$
3. $1.34mMHCl$
4. $0.1MC{H}_{3}COOH$

Q. Which of the following has the same pH as 1 L of a 0.1 M $C{H}_{3}COOH$ solution?
$K_a=1.8\times {10}^{-5}$ for $C{H}_{3}COOH$
Take $(1.34{)}^2=1.8$

1. $3mMHCOOH(K_a=6\times {10}^{-4})$
2. $0.1MC{H}_{3}COONa$
3. $1.34mMHCl$
4. $0.1MC{H}_{3}COOH$

Q. Calculate the $H^{+}$ ion concentration of a 0.01 N weak monobasic acid. The value of dissociation constant is $4.0\times {10}^{-10}$.

1. $2\times {10}^{-6}mole{L}^{-1}$
2. $2\times {10}^{-5}mole{L}^{-1}$
3. $3\times {10}^{-6}mole{L}^{-1}$
4. $3\times {10}^{-5}mole{L}^{-1}$