Embibe Experts Solutions for Chapter: Thermodynamics, Exercise 1: KCET (UG) 2019

Bond enthalpies of ${\mathrm{A}}_2,{ \mathrm{B}}_2$ and $\mathrm{AB}$ are in the ratio $2: 1: 2.$ If bond enthalpy of formation of $\mathrm{AB}$ is $-100 \mathrm{kJ} {\mathrm{mol}}^{-1}.$ The bond enthalpy of ${\mathrm{B}}_2$ is

The reaction in which $\mathrm{\Delta H}>\mathrm{\Delta U}$ is

When the same quantity of heat is absorbed by a system at two different temperatures ${\mathrm{T}}_1$ and ${\mathrm{T}}_2$, such that ${\mathrm{T}}_1>{\mathrm{T}}_2$, change in entropies are $\Delta {\mathrm{S}}_1$ and $\Delta {\mathrm{S}}_2$ respectively. Then: