In the following reaction

${\mathrm{HC}}_2{\mathrm{O}}_4^{-}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{PO}}_4^{3-}<mspace\; width="1em"></mspace>\rightleftharpoons {\mathrm{HPO}}_4^{2-}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{C}}_2{\mathrm{O}}_4^{2-}$ 

Which are the two Bronsted bases ?

1. ${\mathrm{H}}_2{\mathrm{C}}_2{\mathrm{O}}_4^{-}<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{PO}}_4^{3-}$

2. ${\mathrm{HPO}}_4^{2-}<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{C}}_2{\mathrm{O}}_4^{2-}$

3. ${\mathrm{H}}_2{\mathrm{C}}_2{\mathrm{O}}_4^{-}<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{HPO}}_4^{-2}$

4. ${\mathrm{PO}}_4^{3-}<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{C}}_2{\mathrm{O}}_4^{2-}$

Percentage ionisation of water at certain temperature is 3.6 X 10^-7%, Calculate K_w and pH of water.

1. 10^-14, pH = 6.7

2. 4 X 10^-14, pH=6.7

3. 2X 10^-14, pH=7

4. 10^-14, pH=7

A 50 ml solution of strong acid of pH = 1 is mixed with a 50 ml solution of strong acid of pH=2. The pH of the mixture will be nearly:                                                     

(log 5.5 = 0.74)

1. 0.74                   

2. 1.26

3. 3.76                 

4. 4.50

1 litre solution of pH =4 (solution of a strong acid) is added to the 7/3 litre of water. What is the pH of resulting solution. (Log 3 = 0.48)

1. 4

2. 4.48

3. 4.52

4. 5

The pH of a solution obtained by mixing 50ml of 0.4N HCl and 50ml of 0.2M NaOH is:

1. 13

2. 12

3. 1.0

4. 2.0

K_b for a monoacidic base whose 0.10 M solution has a pH of 10.48

1. 9 X 10^-6

2. 9 X 10^-9

3. 9 X 10^-7

4. 3 X 10^-7

In an acidic Buffer solution (CH₃COOH + CH₃COONa), the species mainly present in the solution are:

(Ignore negligible amount)

1. CH₃COOH, CH₃COO^-, CH₃COONa, H⁺

2. CH₃COO^-, Na⁺, CH₃COOH

3. CH₃COONa, CH₃COO-, H⁺

4. CH₃COO^-, Na⁺, H⁺, CH₃COONa

What happens to the pH when NH₄Cl is added to an NH₄OH solution?

1. Increases

2. Decreases

3. Remains unchanged

4. First decreases and then increases

The most hydrolyzed salt among the following is-

(Assume that K_b of all weak bases is the same)
1. NH₄Cl
2. CuSO₄
3. AlCl₃
4. All are equally hydrolyzed.

The pH of 10^-6 M CH₃COOH (K_a = 1.8 X 10^-5) is:

1. 5.37

2. In between 6 & 7

3. 7

4. 8.63