The pK_a of acetylsalicylic acid (aspirin) is 3.5. The pH of gastric juice in human stomach is about 2 – 3 and the pH in the small intestine is about 8. Aspirin will be

unionised in the small intestine and in the stomach
completely ionised in the small intestine and in the stomach
ionised in the stomach and almost unionised in the small intestine
ionised in the small intestine and almost unionised in the stomach

Solution

Aspirin is a weak acid. Due to common ion effect, it is unionised in acid medium but completely ionised in alkaline medium.

Which of the following is most soluble ?

Bi₂S₃ (K_sp= 1 × 10^–17)
MnS (K_sp= 7 × 10^–16)
CuS(K_sp= 8 × 1010^–37)
Ag₂S (K_sp = 6 × 1010^–51)

Solution

If the solubility of PbCl₂ at 25°C is 6.3 × 10^–3 mole/litre, its solubility product at that temperature is

(6.3× 10^–3) × (12.6× 10^–3)²
(6.3 × 10^–3)²× (12.6 × 10^–3)
(6.3 × 10^–3) × (12.6× 10^–3)
(12.6 × 10^–3) × (12.6 × 10^–3)

Solution

At 298 K_a 0.1 M CH₃COOH solution is 1.34% ionized. The ionization constant K_a for acetic acid will be

1.82 × 10^–5
18.2 × 10^–5
0.182 × 10^–5
None of these

Solution

Solution

Solution

In presence of little H₂SO₄(as catalyst) about 2/3 mole of each of CH₃COOH and C₂H₅OH react to form 2/3 mole of the product at equilibrium.

Solution

The dissociation constant of two acids HA₁ and HA₂ are 3.14 × 10^–4 and 1.96 × 10^–5 respectively. The relative strength of the acids will be approximately

1 : 4
4 : 1
1 : 16
16 : 1