How much water should be added to 400 mL of HCI solution in order to raise the pH by one unit?

1.	360 mL	2.	1000 mL
3.	600 mL	4.	3600 mL

Vapour density of ${\mathrm{N}}_2{\mathrm{O}}_4$ when heated to $100°\mathrm{C}$ becomes 24.5. its degree of dissociation at this temperature is

1. 80%

2. 87.75%

3. 40.34%

4. 60%

For the equilibrium  SO₂CI₂(g) ⇌ SO₂(g) + CI₂(g)  volume is increased.
When the equilibrium is re-established then: 

1. amount of  SO₂(g)  will decrease

2. amount of  SO₂CI₂(g)  will increase

3. amount of CI₂(g)  will increase

4. amount of CI₂(g) will remain unchanged

In the reaction A(g) + 2B(g) ⇌ 2C(g) + D(g), the initial concentration of B is twice that of A and, at equilibrium, the concentrations of A and D are equal. The value of the equilibrium constant will be:

$2\mathrm{HI}\stackrel{}{\rightleftharpoons }{\mathrm{H}}_2+{\mathrm{I}}_2$ for 22% dissociation what would be the value of equilibrium constant?

1. 0.04

2. 0.0198

3. 0.5

4. 1.2527

The degree of hydrolysis of the salt is independent of the concentration of a solution: 
1. NH₄CI
2. NH₄CN
3. (NH₄)₂SO₄
4. All of the above

The dissociation of solid ${\mathrm{NH}}_4\mathrm{SH}$ in a closed container produces a pressure of 4 atm at $95°\mathrm{C}$, then ${\mathrm{K}}_{\mathrm{p}}$ for the reaction will be:

${\mathrm{NH}}_4\mathrm{SH}\left(\mathrm{s}\right)\stackrel{}{\rightleftharpoons }{\mathrm{NH}}_3\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{S}\left(\mathrm{g}\right)$

The number of ${\mathrm{H}}^{\oplus }$ ions present in 1 ml of a solution whose pH= 4 , is given as:

($N_A=$ $Avogadro\text{'}s$ $number$)

1. ${10}^{-7}{N}_A$

2. ${10}^{-8}{N}_A$

3. ${10}^{-16}{N}_A$

4. ${10}^{-14}{N}_A$

If the pH of an acidic buffer is 5.7 and ${\mathrm{pK}}_{\mathrm{a}}$ is 5 then the ratio of $\frac{\left[\mathrm{Salt}\right]}{\left[\mathrm{Acid}\right]}$ will be:

On adding NH₄CI to an NH₄OH solution, the pH of the solution will