Explain why the partial pressure $p$ of a gas is proportional to its concentration $c$.

(N/A) For reactions involving gases,it is often convenient to express the equilibrium constant in terms of partial pressure.
The ideal gas equation is given by $pV = nRT$ (Eq. $i$).
Rearranging for pressure,we get $p = (n/V)RT$ (Eq. $ii$).
Since concentration $c$ is defined as $n/V$ (in $mol \ L^{-1}$ or $mol \ dm^{-3}$),we can substitute this into the equation:
$p = cRT$ (Eq. $iii$).
Here,$R$ is the universal gas constant,$T$ is the temperature in Kelvin,and $c$ is the molar concentration of the gas.
At a constant temperature $(T)$,the product $RT$ is constant.
Therefore,the partial pressure $p$ of the gas is directly proportional to its concentration $c$,expressed as $p \propto c$ or $p \propto [\text{gas}]$.