Question

The entropy change when two moles of an ideal monoatomic gas is heated from ${200}^{\circ }\text{C}\text{to}{300}^{\circ }\text{C}$ reversibly and isochorically?

• A. $3R\ln \left(\frac{573}{473}\right)$
• B. $\frac{3}{2}R\ln \left(\frac{573}{473}\right)$
• C. $\frac{3}{2}R\ln \left(\frac{300}{200}\right)$
• D. $\frac{5}{2}R\ln \left(\frac{573}{273}\right)$

Answer 1

The correct option is A $3R\ln \left(\frac{573}{473}\right)$

$\Delta S=n{C}_v\ln \left(\frac{T_2}{T_1}\right)$ for isochoric change.
$\Delta S=2\times \left(\frac{3}{2}R\right)\ln \left(\frac{573}{473}\right)$
$\Delta S=3R\ln \left(\frac{573}{473}\right)$.