NEET NCERT Chemistry Thermodynamics Questions,answers,mcqs,PDFs



Which one is true for the isobaric process?

[A] Δ P = 0
[B] Δ q = 0
[C] Δ H=0
[D] Δ U = 0


A process in which volume remains constant

[A] Isochoric
[B] Isothermal
[C] Adiabatic
[D] isobaric


What is difference between change in enthalpy and change internal energy at constant volume?

[A] 0
[B] VdP
[C] -VdP
[D] +PdV


In which process, net work done by the gas is zero?

[A] Cyclic
[B] Isobaric
[C] Free expansion
[D] Adiabatic


Two moles of ideal gas expands spontaneously into vacuum. The work done will be

[A] ∝(proportional)
[B] 2J
[C] 9 J
[D] Zero


Which of following is correct for free expansion of aii ideal gas under adiabatic conditions?

[A] q = 0, Δ T ≠ 0, w = 0
[B] q ≠ 0, Δ T = 0, w = 0
[C] q = 0, Δ T = 0, w = 0
[D] q = 0, Δ T < 0, w ≠ 0


A system does 100 I work on surroundings by absorbing 150 J of heat Calculate the change in internal energy.

[A] 50J
[B] -50 J
[C] 100 J
[D] -100 J


A gas absorbs 200 J of heat and expands against the external pressure of 5 atm from a volume of 0.5 L to 1 L. Calculate change in internal energy.

[A] -55.5J
[B] -110.2J
[C] 92J
[D] +124.025J


The relationship between enthalpy change and Internal energy change is

[A] Δ H = Δ U + P Δ V
[B] Δ H = Δ U + V Δ P
[C] Δ H = Δ U – P Δ V
[D] Δ H = P Δ V – Δ U


Calculate the work performed when 2 moles of hydrogen expands isothermally and reversibly at 25&8451; from 15 to 45 L

[A] -1.309.70 Calories
[B] 1309.7 Calories
[C] 1210.2 Calories
[D] 1402.7 Calories


The enthalpy of formation of methane at constant pressure and 300 K is -783 KJ. What will be the heat of formation at constant volume? (R = 8.3JK-1 mol-1)

[A] 42 KJ
[B] 22 KJ
[C] -73.34 KJ
[D] 79.2 KJ


For an ideal gas expanding adiabatilly in a vacuum

[A] Δ H = 0
[B] Δ H > 0
[C] Δ H<0
[D] None of these


Pressure-volume (PV) work done by an ideal gas system at constant volume is where E is internal energy of system.

[A] a) \(\frac{ΔP}{P}\)
[B] b) 0
[C] –V Δ P
[D] -Δ E


Which is correct at equilibrium?

[A] ΔG° =0
[B] ΔG = 0
[C] ΔS = 0
[D] ΔE = 0


For a sample of perfect gas, when its pressure changes isothermally from Pi to Pf the entropy change is given by

[A] ΔS= nRIn\(\frac{Pf}{Pi}\)
[B] ΔS=nRIn\(\frac{Pi}{Pf}\)
[C] ΔS = nRT In \(\frac{Pf}{Pi}\)
[D] ΔS=RT\(\frac{Pi}{Pf}\)


Which of the following is the correct equation?

[A] Δ U = Δ W + Δ Q
[B] Δ U = Δ Q – W
[C] Δ W = Δ U + Δ Q
[D] None of these


3 L of an ideal gas at a pressure of (10 atm expands isothermally into a vacuum until its total volume is 10 L How much heat is absorbed and how much work is done in die expansion?

[A] 0
[B] 9
[C] 10
[D] 90


The work done by a system is(10J when 50J heat is supplied to it Calculate the Increase in the internal energy of the system.

[A] 40 J
[B] 20 J
[C] 80 J
[D] -60 J


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

[A] reduced to half
[B] be double
[C] remain constant
[D] Increase four times


The state of gas can be described by quoting the relationship between:

[A] Pressure, Volume, Temperature
[B] Temperature, Amount, Pressure
[C] Amount, Volume, Temperature
[D] Pressure. Volume, Temperature, Amount


4 moles of ideal gas expands reversibly from a volume of 4 dm3 to 40 dm3 at a temperature of 27&8451; Calculate change in entropy.

[A] 1012 JK – 1
[B] 79828 JK -1
[C] 765.88 JK -1
[D] 292.5 JK – 1


Which of die following is an isoentropic process?

[A] Isothermal Process
[B] Adiabatic Process
[C] Isobaric Process
[D] Isochoric Process


For which process Δ U = 0 holds true?

[A] Isochoric
[B] Adiabatic
[C] Both (a) & (b)
[D] None of these