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 need to analyze each equilibrium in terms of the states of matter involved and the concept of changes in the number of moles of gas.

### Step-by-Step Solution:

1. **Identify the Equilibria**:
- Equilibrium I: \( A(s) \rightleftharpoons B(s) \) (Solid to Solid)
- Equilibrium II: \( A(s) \rightleftharpoons B(l) \) (Solid to Liquid)
- Equilibrium III: \( A(l) \rightleftharpoons B(l) \) (Liquid to Liquid)
- Equilibrium IV: \( A(g) \rightleftharpoons B(g) \) (Gas to Gas)

2. **Analyze Equilibrium I**:
- This equilibrium involves only solids. According to Le Chatelier's principle, changes in pressure do not affect solid equilibria. Therefore, **Equilibrium I will not be disturbed by an increase in pressure**.

3. **Analyze Equilibrium II**:
- This equilibrium involves a solid and a liquid. Similar to the first equilibrium, pressure changes do not affect equilibria involving solids and liquids. Thus, **Equilibrium II will not be disturbed by an increase in pressure**.

4. **Analyze Equilibrium III**:
- This equilibrium involves two liquids. Again, pressure changes do not affect liquid equilibria. Therefore, **Equilibrium III will not be disturbed by an increase in pressure**.

5. **Analyze Equilibrium IV**:
- This equilibrium involves gases. Changes in pressure can affect gaseous equilibria. According to Le Chatelier's principle, if the number of moles of gas changes, the equilibrium will shift in the direction that reduces the pressure. However, if the change in the number of moles of gas (\( \Delta n \)) is zero (i.e., the number of moles of gaseous reactants equals the number of moles of gaseous products), then the equilibrium will not be disturbed by pressure changes. Therefore, **Equilibrium IV will not be disturbed by an increase in pressure** if \( \Delta n = 0 \).

### Conclusion:
None of the given equilibria (I, II, III, or IV) will be disturbed by an increase in pressure.