Write the expressions for `K_p` and `K_e` (whichever is applicable) for the following reversible reactions at equilibrium:
(i) `2H_2S(g)+3O_2(g)hArr 2H_2O(g)+2SO_2(g)`
(ii) `2NO(g)+O_2(g)hArr 2NO_(2)(g)`
(iii) `HF(aq.)+H_2O(l) hArr H_(3)O^(+)(aq.)+F(aq.)`

Explanation

To solve the problem, we will write the expressions for \( K_p \) and \( K_c \) for the given reversible reactions at equilibrium.

### Step-by-Step Solution:

**(i)** For the reaction:
\[ 2H_2S(g) + 3O_2(g) \rightleftharpoons 2H_2O(g) + 2SO_2(g) \]

1. **Write the expression for \( K_c \)**:
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