Q43 / 170 · Manipal (MET) 2015 · Chemistry

Enthalpy is equal to

  • A
    $T^2\left[\frac{\delta(G / T)}{\delta T}\right]_p$
  • Correct answer
    B
    $-T^2\left[\frac{\delta(G / T)}{\delta T}\right]_p$
  • C
    $T^2\left[\frac{\delta(G / T)}{\delta T}\right]_V$
  • D
    $-T^2\left[\frac{\delta(G / T)}{\delta T}\right]_V$

Solution

The Gibbs-Helmholtz equation is as $G=H+T\left[\frac{\delta G}{\delta T}\right]_p$ Dividing above equation by $T^2$ $\frac{G}{T^2}=\frac{H}{T^2}+\frac{1}{T}\left[\frac{\delta G}{\delta T}\right]_p$ This on rearrangement becomes. $\left[\frac{\delta(G / T)}{\delta T}\right]=-\frac{H}{T^2}$ Thus, enthalpy, $H=-T^2\left[\frac{\delta G / T}{\delta T}\right]_p$ Where, $\quad H=$ enthalpy

Hence, the correct answer is option: 'B'.

Relevant Questions