Question

Molar enthalpy change for melting of ice is $6\, kJ / mol$. Then the internal energy change (in $k J / mol$ ) when $1$ mole of water is converted into ice at $1$ atm at $0^{\circ} C$ is Empty QImg

• A. RT/1000
• B. 6
• C. 6-(RT/1000)
• D. 6+(RT/1000)

Answer 1

Answer: (B)

Given, $\Delta H=6\, kJ / mol$
$\Delta U=?$
$H_{2} O(l) Ice(s)$
$\because \Delta H=\Delta U+\Delta n_{g} R T$
Here, $\Delta n_{g}=0$
$\therefore \Delta H=\Delta U$
$\Rightarrow \Delta U=6\, kJ / mol$