A quantity of $4.0$ moles of an ideal gas at $20°\mathrm{C}$ expands isothermally against a Constant pressure of $2.0\mathrm{ }\mathrm{a}\mathrm{t}\mathrm{m}$ from $1.0\mathrm{ }\mathrm{L}$ to $10.0\mathrm{ }\mathrm{L}$. If entropy change of system is

•  As volume increases, entropy values also increases because disorders increases.
•  The expression for entropy change with respect to volume is

                        $\mathrm{\Delta S}=2.303{\mathrm{nRlogV}}_2/{\mathrm{V}}_1$;

 by substituting all values, $\mathrm{R}=2,\mathrm{n}=4,{\mathrm{V}}_1=1$, $V_2=10$

 $\mathrm{\Delta S}=2.303\times 4\times 2\times \log 10/1; (\log 10=1)$

 $\mathrm{\Delta S}=2.303\times 8=18.424$