Thermodynamics practice · Mixed difficulty

The heat evolved on combustion of $1 \, \mathrm{gm}$ of starch, $\left({C}_6 {H}_{10}{O}_5\right)$, into ${CO}_2({g})$ and ${H}_2 {O}({l})$ is $4.18 \, \text{Kcal}.$ What is the standard enthalpy of formation of $1 \, \mathrm{gm}$ of starch? Heat of formation of ${CO}_2({g})$ and ${H}_2 {O}({l})$ are $-94.05$ and $-68.32 \, \mathrm{Kcal} / \mathrm{mol}$.

At 27℃ one mole of an ideal gas is compressed isothermally and reversible from a pressure of 2 atm to 10 atm. The value of ∆E and q are (R=2 cal)

An engine operating between 150℃ and 25℃ takes 500 J heat from a higher temperature reservoir if there are no frictional losses, then work done by engine is

Heat of formation of two moles of $\mathrm{NH}_3(\mathrm{~g})$ is $-90 \mathrm{KJ}$. Bond energies of $\mathrm{H}-\mathrm{H}$ and $\mathrm{N}-\mathrm{H}$ bonds are $435 \mathrm{KJ}$ and $390 \mathrm{KJ} \mathrm{mol}^{-1}$ respectively. The value of the bond energy of $N=N$ will be

At the same conditions of pressure, volume and
temperature, work done is maximum for which
gas if all gases have equal masses?

The standard heat of combustion of solid boron is :

A gas expands isothermally and reversibly. The work done by the gas is:

Which of the following factors do not affect heat capacity?

If,$\mathrm{S} + {\mathrm{O}_2} \to \mathrm{S}{\mathrm{O}_2};∆H = - 298.2\mathrm{kJ}$...(i)$\mathrm{S}{\mathrm{O}_2} + \frac{1}{2}{\mathrm{O}_2} \to \mathrm{S}{\mathrm{O}_3};∆H = - 98.7\mathrm{kJ}$...(ii)$\mathrm{S}{\mathrm{O}_3} + {\mathrm{H}_2}\mathrm{O} \to {\mathrm{H}_2}\mathrm{S}{\mathrm{O}_4};∆H = - 130.2\mathrm{kJ}$...(iii)${\mathrm{H}_2} + \frac{1}{2}{\mathrm{O}_2} \to {\mathrm{H}_2}\mathrm{O};∆H = - 227.3\mathrm{kJ}$...(iv)The enthalpy of formation of ${\mathrm{H}_2}\mathrm{S}{\mathrm{O}_4}$ at 298 K will be:

The enthalpy of vapourisation of a certain liquid at its boiling point of ${35^0}C$ is $24.64\,\,KJ/mol$. The value of change in entropy for the process is

Workdone for the conversion of 0.5 mole of water at $100^{\circ} \mathrm{C}$ to steam at $1 \mathrm{~atm}$ pressure is (heat of vaporisation of water at $100^{\circ} \mathrm{C}$ is $40670 \mathrm{~J} \mathrm{~mol}^{-1}$ )

For a reaction, ∆H=9.08 kJ $mo{l^{ - 1}}$ and ∆S=35.7 J${K^{ - 1}}mo{l^{ - 1}}$. Which of the following statement is correct for the reaction?

For an isothermal free expansion of an ideal gas correct option is:

The enthalpy of formation of ammonia gas at 298 K is - 46.11 kJ $\mathrm{mo}{\mathrm{l}^{ - 1}}$. The equation to which this value relates is:

The temperature coefficient of e.m.f. of a cell can be given by:

$\Delta \,U$ is equal to

Vibrational energy is:

Consider the following reaction occurring in an automobile

$2 {C}_8 {H}_{18}({~g})+25 {O}_2({~g}) \longrightarrow 16 {CO}_2({~g})+18 {H}_2 {O}({g})$

the sign of $\Delta {H}, \Delta {S}$ and $\Delta {G}$ would be

Given,

$\mathrm{KOH}(\mathrm{aq})+\mathrm{HCl}(\mathrm{aq}) \longrightarrow \mathrm{KCl}(\mathrm{aq})+\mathrm{H}_2 \mathrm{O}(l); \Delta H=-57.3 \mathrm{~kJ} \mathrm{~mol}^{-1} \ldots (i)$

$\mathrm{H}_2(\mathrm{~g})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g}) \longrightarrow \mathrm{H}_2 \mathrm{O}(\mathrm{l}); \Delta \mathrm{H}=-286.2 \mathrm{~kJ} \mathrm{~mol}^{-1} \ldots.....(ii)$

$\frac{1}{2} \mathrm{H}_2(\mathrm{~g})+\frac{1}{2} \mathrm{Cl}_2(\mathrm{~g}) \xrightarrow{A q} \mathrm{HCl}(\mathrm{aq}); \Delta H=-164.4 \mathrm{~kJ} \mathrm{~mol}^{-1} \ldots(\mathrm{iii)}$

$\mathrm{K}(\mathrm{s})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g})+\frac{1}{2} \mathrm{H}_2(\mathrm{~g})+\mathrm{aq} \longrightarrow \mathrm{KOH}(\mathrm{aq}) ; \Delta H=-487.4 \mathrm{~kJ} \mathrm{~mol}^{-1} \ldots(\mathrm{iv})$

$\mathrm{KCl}(\mathrm{s})+\mathrm{aq} \longrightarrow \mathrm{KCl}(\mathrm{aq}); \Delta H=+18.4 \mathrm{~kJ} \mathrm{~mol}{ }^{-1}$.....(v)

Heat of formation of $\mathrm{KCl}$ will be

A process has $\Delta H = 200J\mathrm{ }mo{l^{ - 1}}$ and $\Delta S = 40J{K^{ - 1}}mo{l^{ - 1}}\,$. Out of the values given below, choose the minimum temperature above which the process will be spontaneous

The standard entropies of ${N_2}(g),\,\,{H_2}(g)$ and $N{H_3}(g)$ are $191.5,\,\,130.5,\,\,192.6\,\,\,\mathrm{J}{\mathrm{K}^{\mathrm{ - 1}}}\,\mathrm{mo}{\mathrm{l}^{\mathrm{ - 1}}}$. The value of $\Delta S^\circ$ formation of ammonia is

Which reaction is endothermic in nature?

For an adiabatic expansion of a perfect gas ∆P/P is equal to:

The volume of gas is reduced to half from its original volume. The specific heat will be

$\Delta H$ for $\mathrm{CaCO}_3(\mathrm{s}) \rightarrow \mathrm{CaO}(\mathrm{s})+\mathrm{CO}_2(\mathrm{g})$ is $176 \mathrm{~kJ} \mathrm{~mol}^{-1}$ at $1240 \mathrm{~K}.$ The $\Delta U$ for the reaction is equal to

Assuming that water vapours are ideal gas. The change in internal energy (∆U) when 1 mol of water is vaporized at 1 bar pressure and 100C. (Given molar enthalpy of vaporization at 1 bar and 373 K is 41 kJ $\mathrm{mo}{\mathrm{l}^{ - 1}}$ and R=8.3 J $\mathrm{mo}{\mathrm{l}^{ - 1}}$ ${K^{ - 1}}$) will be:

∆H for $\mathrm{CaC}{\mathrm{O}_3}\left( s \right)$$\to \mathrm{CaO}\left( s \right) + \mathrm{C}{\mathrm{O}_2}\left( \mathrm{g} \right)$ is 176 kJ$mo{l^{ - 1}}$ at 1240 K. The ∆U for the change is equal to:

Choose intensive properties in the following:
(i) density $\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$ (ii) specific volume $\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$ (iii) Heat capacity
(iv) mole $\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$ (v) concentration $\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,$ (vi) volume

In an isobaric process, the ratio of heat supplied to the system (dθ) and work done by the system (dW) for diatomic gas is

Assertion : Many endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature.
Reason : Entropy of the system increases with increase in temperature.