<p>1 mole of rigid diatomic gas performs a work of&nbsp;<span class="equation">\(\frac{Q}{5}\)</span>&nbsp;when heat Q is supplied to it. The molar heat capacity of the gas during this transformation is&nbsp;<span class="equation">\(\frac{xR}{8}\)</span>​​​​​​​. The value of x is _________. [R = universal gas constant]</p>