What will be the effect of increased pressure on the following equilibria :
(i)`N_2(g) + 3H_2(g) hArr 2NH_3(g)`
(b) `N_2O_4(g) hArr 2NO_2(g)`
(iii)`2SO_2(g) + O_2(g) hArr 2SO_3(g)`
(iv)`H_2(g) +I_2(g) hArr 2HI(g)`

Explanation

To determine the effect of increased pressure on the given equilibria, we can apply Le Chatelier's principle. This principle states that if an external change is applied to a system at equilibrium, the system will adjust itself to counteract that change and restore a new equilibrium.

### Step-by-Step Solution:

**(i) For the equilibrium: `N_2(g) + 3H_2(g) ⇌ 2NH_3(g)`**

1. **Count the moles of gas on each side:**
- Left side: 1 (N₂) + 3 (H₂) = 4 moles
...