Thermodynamics · Chemistry · NEET

MCQ (Single Correct Answer)

Choose the correct statement for the work done in the expansion and heat absorbed or released when 5 litres of an ideal gas at 10 atmospheric pressure isothermally expands into vacuum until volume is 15 litres :

NEET 2024 (Re-Examination)

For an endothermic reaction:

(A) $$\mathrm{q}_{\mathrm{p}}$$ is negative.

(B) $$\Delta_{\mathrm{r}} \mathrm{H}$$ is positive.

(D) $$\mathrm{q}_{\mathrm{p}}$$ is positive.

Choose the correct answer from the options given below:

NEET 2024 (Re-Examination)

For the following reaction at $$300 \mathrm{~K}$$

$$\mathrm{A}_2(\mathrm{~g})+3 \mathrm{~B}_2(\mathrm{~g}) \rightarrow 2 \mathrm{AB}_3(\mathrm{~g})$$

the enthalpy change is $$+15 \mathrm{~kJ}$$, then the internal energy change is :

NEET 2024 (Re-Examination)

In which of the following processes entropy increases?

A. A liquid evaporates to vapour.

B. Temperature of a crystalline solid lowered from $$130 \mathrm{~K}$$ to $$0 \mathrm{~K}$$.

C. $$2 \mathrm{NaHCO}_{3(\mathrm{~s})} \rightarrow \mathrm{Na}_2 \mathrm{CO}_{3(\mathrm{~s})}+\mathrm{CO}_{2(\mathrm{~g})}+\mathrm{H}_2 \mathrm{O}_{(\mathrm{g})}$$

D. $$\mathrm{Cl}_{2(g)} \rightarrow 2 \mathrm{Cl}_{(g)}$$

Choose the correct answer from the options given below:

NEET 2024

Match List I with List II.

	List I (Process)		List II (Conditions)
A.	Isothermal process	I.	No heat exchange
B.	Isochoric process	II.	Carried out at constant temperature
C.	Isobaric process	III.	Carried out at constant volume
D.	Adiabatic process	IV.	Carried out at constant pressure

Choose the correct answer from the options given below:

NEET 2024

The work done during reversible isothermal expansion of one mole of hydrogen gas at $$25^{\circ} \mathrm{C}$$ from pressure of 20 atmosphere to 10 atmosphere is (Given $$\mathrm{R}=2.0 \mathrm{~cal} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$)

NEET 2024

Consider the following reaction :-

$$2 \mathrm{H}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \rightarrow 2 \mathrm{H}_2 \mathrm{O}(\mathrm{g}) \Delta_{\mathrm{r}} \mathrm{H}^{\circ}=-483.64 \mathrm{~kJ} \text {. }$$

What is the enthalpy change for decomposition of one mole of water? (Choose the right option).

NEET 2023 Manipur

The equilibrium concentrations of the species in the reaction $$\mathrm{A}+\mathrm{B} \rightleftharpoons \mathrm{C}+\mathrm{D}$$ are $$2,3,10$$ and $$6 \mathrm{~mol}$$ $$\mathrm{L}^{-1}$$, respectively at $$300 \mathrm{~K} . \Delta \mathrm{G}^{0}$$ for the reaction is $$(\mathrm{R}=2 \mathrm{cal} / \mathrm{mol} ~\mathrm{K})$$

NEET 2023

Which amongst the following options is the correct relation between change in enthalpy and change in internal energy?

NEET 2023

One mole of an ideal gas at 300 K is expanded isothermally from 1 L to 10 L volume. $$\Delta$$U for this process is :

(Use R = 8.314 J k^$$-$$1 mol^$$-$$1)

NEET 2022 Phase 2

A vessel contains 3.2 g of dioxygen gas at STP (273.15 K and 1 atm pressure). The gas is now transferred to another vessel at constant temperature, where pressure becomes one third of the original pressure. The volume of new vessel in L is : (Given : molar volume at STP is 22.4 L)

NEET 2022 Phase 2

Which of the following p-V curve represents maximum work done?

NEET 2022 Phase 1

Which one among the following is the correct option for right relationship between C_P and C_V for one mole of ideal gas?

NEET 2021

For irreversible expansion of an ideal gas under isothermal condition, the correct option is :

NEET 2021

Hydrolysis of sucrose is given by the following reaction.
Sucrose + H₂O ⇌ Glucose + Fructose
If the equilibrium constant (K_c) is 2 $$ \times $$ 10¹³ at 800 K, the value of $$\Delta r{G^\Theta }$$ at the same temperature will be :

NEET 2020 Phase 1

For the reaction, 2Cl(g) $$ \to $$ Cl₂(g), the correct option is :

NEET 2020 Phase 1

The correct option for free expansion of an ideal gas under adiabatic condition is :

NEET 2020 Phase 1

In which case change in entropy is negative?

NEET 2019

Under isothermal condition, a gas at 300 K expands from 0.1 L to 0.25 L against a constant external pressure of 2 bar. The work done by the gas is [Given that 1 L bar = 100 J]

NEET 2019

The bond dissociation energies of X₂ , Y₂ and XY are in the ratio of 1 : 0.5 : 1. $$\Delta $$H for the formation of XY is –200 kJ mol^–1. The bond dissociation energy of X₂ will be

NEET 2018

A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy $$\Delta $$U of the gas in joules will be

NEET 2017

For a given reaction, $$\Delta $$H = 35.5 kJ mol^$$-$$1 and $$\Delta $$S = 83.6 J K^$$-$$1 mol^$$-$$1. The reaction is spontaneous at (Assume that $$\Delta $$H and $$\Delta $$S do not vary with temperature.)

NEET 2017

For a sample of perfect gas when its pressure is changed isothermally from p_i to p_f, the entropy change is given by

NEET 2016 Phase 2

The heat of combination of carbon to CO₂ is $$-$$393.5 kJ/mol. The heat released upon formation of 35.2 g of CO₂ from carbon and oxygen gas is

AIPMT 2015

Which of the following statements is correct for the spontaneous adsorption of a gas?

AIPMT 2014

For the reaction, $${X_2}{O_{4\left( l \right)}}\,\, \to \,\,2X{O_{2(g)}}$$

$$\Delta $$U = 2.1 kcal, $$\Delta $$S = 20 cal K^$$-$$1 at 300 K

Hence, G is

AIPMT 2014

Three thermochemical equations are given below
(i)  C_(graphite) + O_2(g) $$ \to $$ CO_2(g); $$\Delta $$_rH^o = x kJ mol^$$-$$1
(ii)  C_(graphite) + $${1 \over 2}$$O_2(g) $$ \to $$ CO_(g); $$\Delta $$_rH^o = y kJ mol^$$-$$1
(iii)  CO_(g) + $${1 \over 2}$$O_2(g) $$ \to $$ CO_2(g); $$\Delta $$_rH^o = z kJ mol^$$-$$1
Based on the above equations, find out which of the relationship given below is correct.

NEET 2013 (Karnataka)

When 5 litres of a gas mixture of methane and propane is perfectly combusted at 0^oC and 1 atmosphere, 16 litres of oxygen at the same temperature and pressure is consumed, The amount of heat released from this combustion in kJ ($$\Delta $$H_comb. (CH₄) = 890 kJ mol^$$-$$1, $$\Delta $$H_comb. (C₃H₈) = 2220 kJ mol^$$-$$1) is

NEET 2013 (Karnataka)

A reaction having equal energies of activation for forward and reverse reactions has

NEET 2013

Standard enthalpy of vaporisation $$\Delta $$_vapH^o for water at 100^oC is 40.66 kJ mol^$$-$$1. The internal energy of vaporisation of water at 100^oC (in kJ mol^$$-$$1) is

AIPMT 2012 Prelims

The enthalpy of fusion of water is 1.435 kcal/mol. The molar entropy change for the melting of ice at 0^oC is

AIPMT 2012 Prelims

In which of the following reactions, standard reaction entropy change ($$\Delta $$S^o) is positive and standard Gibb's energy change ($$\Delta $$G^o) decreases sharply with increasing temperature ?

AIPMT 2012 Prelims

Consider the following processes :

	H (kJ/mol)
1/2A $$ \to $$ B	+150
3B $$ \to $$ 2C + D	-125
E + A $$ \to $$ 2D	+350

For B + D $$ \to $$ E + 2C, $$\Delta $$H will be

AIPMT 2011 Mains

Which of the following is correct option for free expansion of an ideal gas under adiabatic condition ?

AIPMT 2011 Prelims

Enthalpy change for the reaction,
4H_(g) $$ \to $$ 2H_2(g) is $$-$$869.6 kJ
The dissociation energy of H $$-$$ H bond is

AIPMT 2011 Prelims

If the enthalpy change for the transition of liquid water to steam is 30 kJ mol^$$-$$1 at 27^oC, the entropy change for the process would be

AIPMT 2011 Prelims

Match List I (Equations) with List II (Type of processes) and select the correct option.

List I		List II
Equations		Type of processes
A.	K_p > Q	(i)	Non- spontaneous
B.	$$\Delta $$G^o < RT ln Q	(ii)	Equilibrium
C.	K_p = Q	(iii)	Spontaneous and endothermic
D.	T > $${{\Delta H} \over {\Delta S}}$$	(iv)	Spontaneous