Consider the following equilibria:
`I. A(s) hArr B(s), II. A(s) hArr B(l)`
`III. A(l) hArr B(l), IV. A(g) hArr B(g)`
Which of the above will be disturbed by an increase in pressure?

Options

A. II
B. I, II
C. I, II, III,
D. None of these

Explanation

To determine which of the given equilibria will be disturbed by an increase in pressure, we will analyze each equilibrium one by one.

### Step-by-Step Solution:

1. **Equilibrium I: A(s) ⇌ B(s)**
- Both A and B are in the solid state.
- The concentration and density of solids are constant and do not change with pressure.
- **Conclusion**: There will be no effect on this equilibrium due to an increase in pressure.

2. **Equilibrium II: A(s) ⇌ B(l)**
- Here, A is a solid and B is a liquid.
- Similar to the first case, the solid (A) has a constant concentration and density.
- The liquid (B) also has a constant density and concentration.
- **Conclusion**: There will be no effect on this equilibrium due to an increase in pressure.

3. **Equilibrium III: A(l) ⇌ B(l)**
- Both A and B are in the liquid state.
- As mentioned earlier, liquids are incompressible, meaning their density and concentration remain constant.
- **Conclusion**: There will be no effect on this equilibrium due to an increase in pressure.

4. **Equilibrium IV: A(g) ⇌ B(g)**
- Both A and B are in the gaseous state.
- Gases are compressible, and their volume can change with pressure.
- According to Le Chatelier's principle, if pressure is increased, the equilibrium will shift towards the side with fewer moles of gas.
- However, in this case, both sides have equal moles of gas (1 mole of A and 1 mole of B).
- **Conclusion**: There will be no effect on this equilibrium due to an increase in pressure.

### Final Conclusion:
After analyzing all four equilibria, we find that none of them will be disturbed by an increase in pressure.