Thermodynamics practice · Medium

For a perfectly crystalline solid $C_{p, m}=a T^3$, where $a$ is constant. If $C_{p, m}$ is $0.42 \mathrm{~J} / \mathrm{K} \mathrm{~mol} \mathrm{~at} 10 \mathrm{~K}$, molar entropy at $20 \mathrm{~K}$ is :

Consider the following conversions:

(i) $\mathrm{O}_{(g)}+e^{-} \rightarrow O^{-}(g), \Delta H_1$

(ii) $\mathrm{F}_{(g)}+e^{-} \rightarrow F^{-}(g), \Delta H_2$

(iii) $\mathrm{Cl}_{(\mathrm{g})}+\mathrm{e}^{-} \rightarrow \mathrm{Cl}^{-}(\mathrm{g}), \Delta \mathrm{H}_3$

(iv) $\mathrm{O}_{(g)}^{-}+e^{-} \rightarrow O^{2-}(g), \Delta H_4$

That according to given information the incorrect statements is:

An ideal gas is allowed to expand both reversibly and irreversibly in an isolated system. If ${T_i}$ is the initial temperature and ${T_f}$ is the final temperature, which of the following statements is correct?

A gas is allowed to expand in an insulated container against a constant external pressure of 4 atm from the initial volume of 1.8 L to a final volume of 5.2 L. The change in internal energy of the gas is

$16 \mathrm{~gm} \, {O}_2$ is expanded reversibly at $300 \mathrm{~K}$ temperature from $5 \mathrm{~dm}^3$ to $25 \mathrm{~dm}^3$ then find out ${W}$ and ${q}$ (in cal)

Two moles of an ideal gas undergo reversible isothermal expansion from $2.303 \mathrm{~L}$ to $23.03 \mathrm{~L}$ at $27^{\circ} \mathrm{C}$. The change in entropy is: $\left[\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1}\right.$ $\mathrm{mol}^{-1}$]

The enthalpy change is negative for :

Assertion :- Catalyst changes Gibbs free energy of system.

Reason :- Catalyst changes preexpotential factor of a chemical reaction.

In the exothermic reaction, the enthalpy of
reaction is always:

10 moles of an ideal gas compressed from $100\, \mathrm{~L}$ to $10 \,\mathrm{~L}$ reversibly at constant temperature of $27^{\circ} \mathrm{C}$. The entropy change during the process is ( $R=$ Universal gas constant)

Identify the correct statement for change of Gibb’s energy for a system ($\Delta {G_{\mathrm{system}}}$) at constant temperature and pressure:

When $1 \mathrm{~g}$ equivalent of strong acid reacts with strong base, the heat released is $13.5 \mathrm{~kcal}.$ When $1 \mathrm{~g}$ equivalent $\mathrm{H}_2 \mathrm{A}$ is completely neutralized against strong base, $13 \mathrm{~kcal}$ is released. When $1 \mathrm{~g}$ equivalent $\mathrm{B}(\mathrm{OH})_2$ is completely neutralized against strong acid, $10 \mathrm{~kcal}$ heat is released. What is the enthalpy change when 1 mole of $\mathrm{H}_2 \mathrm{A}$ is completely neutralized by $\mathrm{B}(\mathrm{OH})_2?$

$\begin{aligned} & \text {If } \mathrm{H}_2+1 / 2 \mathrm{O}_2 \longrightarrow \mathrm{H}_2 \mathrm{O}, \Delta \mathrm{H}=-68 \mathrm{~kcal} \\ & \mathrm{K}+\mathrm{H}_2 \mathrm{O}+\text {water} \longrightarrow \mathrm{KOH}(\mathrm{aq})+1 / 2 \mathrm{H}_2, \Delta \mathrm{H}=-48 \mathrm{~kcal} \\ & \mathrm{KOH}+\text {water} \longrightarrow \mathrm{KOH}(\mathrm{aq}), \Delta \mathrm{H}=-14 \mathrm{~kcal} \end{aligned}$

Find the heat of formation of $\mathrm{KOH}$.

The bond dissociation energies for $Cl_2, I_2$ and
$ICl$ are 242.3, 151 and 211.3 kJ/mol
respectively. The enthalpy of sublimation of
iodine is 62.8 kJ/mol. What is the standard
enthalpy of formation of $ICl \text{(g)}?$

Which of the following statements is incorrect?

Which one among the following pairs does not
represent example for intensive property?

The change of enthalpy of a chemical reaction is the same whether the reaction takes place in one step or in several steps". This law was presented by

Which one among the following is the correct option for right relationship between ${C_p}\mathrm{ and }{C_v}$ for one mole of ideal gas?

Given that $\Delta H_f(H)=218 \mathrm{~kJ} / \mathrm{mol}$, express the $\mathrm{H}-\mathrm{H}$ bond energy in $\mathrm{k ~cal} / \mathrm{mol}$.

For which among the following reactions,
change in entropy is less than zero

In a chemical reaction ∆H=150 kJ and ∆S=100 $\mathrm{J}{\mathrm{K}^{ - 1}}$ at 300 K. The ∆G for the reaction is:

If one mole of an ideal gas $\left(C_{p, m}=\frac{5}{2} R\right)$ is expanded isothermally at $300 \mathrm{~K}$ until its volume is tripled then $\Delta_{\text {sys }} S$ is

What is the final temperature (in kelvin) of $0.10$ mole monoatomic ideal gas that performs 75 cal of work adiabatically if the initial temperature is $227^{\circ} \mathrm{C}$? (use $\mathrm{R}=2 \mathrm{~cal} / \mathrm{K}-\mathrm{mol}$)

When a certain amount of ethylene was burnt 6226 kJ heat was evolved. If heat of combustion of ethylene is 1411 kJ, the volume of ${{\mathrm{O}_2}}$ (at NTP) that entered into the reaction is:

Using bond energy data, calculate heat of formation of isoprene. Given $\mathrm{BE}$ of $\mathrm{C}-\mathrm{H}=98.8 \mathrm{~kcal}, \mathrm{H}-\mathrm{H}=104 \mathrm{~kcal}, \mathrm{C}-\mathrm{C}=83 \mathrm{~kcal}, \mathrm{C}=\mathrm{C}=147 \mathrm{~kcal}$ and $\mathrm{C}(\mathrm{s}) \longrightarrow \mathrm{C}(\mathrm{g})=171 \mathrm{~kcal}$.

${FeCO}_3(\mathrm{s})$ decomposes at constant pressure as ${FeO}(\mathrm{s})+{CO}_2(\mathrm{g})$

${FeCO}_3(\mathrm{s}) \stackrel{\Delta}{\longrightarrow} {FeO}(\mathrm{s})+{CO}_2(\mathrm{g})$

at $25^{\circ} \mathrm{C}$, the heat absorbed during the reaction is $80 \mathrm{~kJ}$.

Calculate $\Delta H$ & $\Delta U$ for the reaction

Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction?

If $\Delta \mathrm{H}$ is the enthalpy change and $\Delta \mathrm{E}$ the change in internal energy accompanying a gaseous reaction then

The standard heat of combustion of a hydrocarbon compound is an/a-

$\Delta H$ for the reaction $2 \mathrm{C}(\mathrm{s})+3 \mathrm{H}_2(\mathrm{g})\rightarrow \mathrm{C}_2 \mathrm{H}_6(\mathrm{g})$ is $-20.24 \mathrm{~kcal} / \mathrm{mol}.$ The bond energies (in $\mathrm{kcal} / \mathrm{mol}$) of $\mathrm{C}-\mathrm{C}, \mathrm{C}-\mathrm{H}$ and $\mathrm{H}-\mathrm{H}$ are $63 , 85.6$ and $102.6 ,$ respectively. The enthalpy of sublimation of $\mathrm{C}(\mathrm{s})$ is