c
\(\Delta G ^{\circ}=- RT \ell n K _{ eq }\)

Given \(\Delta G ^{\circ}=-9.478 KJ / mole\)

So \(-9.478 \times 10^{3}=-495 \times 8.314 \times \ell n K _{ eq }\)

\(\ell n K _{ eq }=2.303\)

\(=\ell n 10\)

So \(K _{ eq }=10\)

Now \(A ( g ) \rightleftharpoons B ( g )\)

\(\begin{array}{lll} t  =0 & 22  0\end{array}\)

\(\begin{array}{lll}t=t  22-x  x\end{array}\)

\(K _{ eq }=\frac{[ B ]}{[ C ]}=\frac{ x }{22- x }=10\)

or \(x=20\)

So millmoles of \(B =20\)