Derive units for `K_(C )` for the following equilibria.
`(i) CaCO_(3(s)) implies CaO_((s))+CO_(2(g))`
(ii) `PCl_(3(g))+Cl_(2(g))implies PCl_(5(g))`
(iii) `N_(2(g))+O_(2(g)) implies 2NO_((g))`

Explanation

To derive the units for the equilibrium constant \( K_C \) for the given reactions, we will follow a systematic approach. The equilibrium constant \( K_C \) is defined as the ratio of the concentrations of the products to the concentrations of the reactants, each raised to the power of their respective stoichiometric coefficients.

### (i) For the reaction:
\[ \text{CaCO}_3(s) \rightleftharpoons \text{CaO}(s) + \text{CO}_2(g) \]

**Step 1:** Write the expression for \( K_C \).
- Since \( CaCO_3 \) and \( CaO \) are solids, they do not appear in the equilibrium expression. We only consider the gaseous component \( CO_2 \).
- Therefore, the expression for \( K_C \) is:
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