Embibe Experts Solutions for Chapter: Thermodynamics, Exercise 1: EXERCISE-1

What amount of heat energy $\left(\mathrm{kJ}\right)$ is released in the combustion of $12.0 \mathrm{g}$ of ${\mathrm{C}}_3{\mathrm{H}}_4$? (Atomic weights: $\mathrm{C}=12.01,\mathrm{H}=1.008,\mathrm{O}=16.00$).

${\mathrm{C}}_3{{\mathrm{H}}_4}_{\left(\mathrm{g}\right)}+4{{\mathrm{O}}_2}_{\left(\mathrm{g}\right)}\to 3{{\mathrm{CO}}_2}_{\left(\mathrm{g}\right)}+2{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}$

$∆\mathrm{H}°=-1939.1\mathrm{kJ}$

The standard heat of combustion of solid boron is equal to:-

In the reaction, ${\mathrm{CO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)\to \mathrm{CO}\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right); ∆\mathrm{H}=2.8\mathrm{kJ} ∆\mathrm{H}$ represents:-

A gas mixture $3.67 \mathrm{L}$ in volume contain ${\mathrm{C}}_2{\mathrm{H}}_4$ and ${\mathrm{CH}}_4$ is proportion of $2:1$ by moles and is at $25°\mathrm{C}$ and $1\mathrm{atm}$. If the $∆{\mathrm{H}}_{\mathrm{C}}\left({\mathrm{C}}_2{\mathrm{H}}_4\right)$ and $∆{\mathrm{H}}_{\mathrm{C}}\left({\mathrm{CH}}_4\right)$ are $-1400$ and $-900\mathrm{kJ}/\mathrm{mole}$ find heat evolved on burning this mixture:-

The enthalpy change for the following reaction is $514 \mathrm{kJ}$. Calculate the average $\mathrm{Cl}-\mathrm{F}$ bond energy.

${\mathrm{ClF}}_3\left(\mathrm{g}\right)\to \mathrm{Cl}\left(\mathrm{g}\right)+3\mathrm{F}\left(\mathrm{g}\right)$

Given the following equations and $∆\mathrm{H}°$ values, determine the heat of reaction $\left(\mathrm{kJ}\right)$ at $298 \mathrm{K}$ for the reaction:

$4{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)+3\mathrm{Fe}\left(\mathrm{s}\right)\to {\mathrm{Fe}}_3{\mathrm{O}}_4\left(\mathrm{s}\right)+4{\mathrm{H}}_2\left(\mathrm{g}\right)$

${\mathrm{H}}_2\left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$                     $\frac{∆\mathrm{H}°}{\mathrm{kJ}}=-285.8$

$3\mathrm{FeO}\left(\mathrm{s}\right)+\frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{Fe}}_3{\mathrm{O}}_4\left(\mathrm{s}\right)$            $\frac{∆\mathrm{H}°}{\mathrm{kJ}}=-302.4$

$\mathrm{FeO}\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)\to \mathrm{Fe}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$       $\frac{∆\mathrm{H}°}{\mathrm{kJ}}=-13.8$

The standard heat of combustion of $\mathrm{Al}$ is $-837.8\mathrm{kJ} {\mathrm{mol}}^{-1}$ at $25°\mathrm{C}$ which of the following releases $250\mathrm{kcal}$ of heat:-..

If heat of dissociation of ${\mathrm{CHCl}}_2\mathrm{COOH}$ is $0.7\mathrm{kcal}/\mathrm{mole}$ then $∆\mathrm{H}$ for the reaction:-

${\mathrm{CHCl}}_2\mathrm{COOH}+\mathrm{KOH}\to {\mathrm{CHCl}}_2\mathrm{COOK}+{\mathrm{H}}_2\mathrm{O}$.

(heat of neutralisation is$13.7\mathrm{kj} {\mathrm{mol}}^{-1}$)