 # NEET Thermodynamics Questions : NEET Previous Year questions

1. Which of the following are not state functions?                                 (2008)

(I) q + w                               (II) q

(III) w                                  (IV) H – TS

(a) (I), (II) and (III)            (b) (II) and (III)

(c) (I) and (IV)                   (d) (II), (III) and (IV)

Chemistry Notes

Physics Notes

Biology Notes

(a) q = 0, ΔT = 0 and w = 0

(b) q = 0, ΔT < 0 and w > 0

(c) q < 0, ΔT = 0 and w = 0

(d) q > 0, ΔT > 0 and w > 0

5. Under isothermal conditions, 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)

(a) 30 J                            (b) –30 J

(c) 5 kJ                            (d) 25 J

6. (NEET 2019)

(b) TA = TB

(d) TC = TA

7. An ideal gas expands isothermally from 10–3 m3 to 10–2 m3 at 300 K against a constant pressure of 105 N m–2. The work done on the gas is  (NEET 2019)

(a) +270 kJ                 (b) –900 J

(c) +900 kJ                 (d) –900 kJ

8. 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 ΔU of the gas in joules will be                                                (NEET 2017)

(a) –500 J                       (b) –505 J

(c) +505 J                       (d) 1136.25 J

9. Equal volumes of two monatomic gases, A and B at same temperature and pressure are mixed. The ratio of specific heats (CP/CV) of the mixture will be                   (2012)

(a) 0.83                             (b) 1.50

(c) 3.3                               (d) 1.67

10. Which of the following is correct option for free expansion of an ideal gas under adiabatic condition?                                                     (2011)

(a) q = 0, ΔT ≠ 0, w = 0                      (b) q ≠ 0, ΔT = 0, w = 0

(c) q = 0, ΔT = 0, w = 0                      (d) q = 0, ΔT < 0, w ≠ 0

11. Three moles of an ideal gas expanded spontaneously into vacuum. The work done will be                                                              (Mains 2010)

(a) Infinite              (b) 3 Joules

(c) 9 Joules            (d) zero.

12. Assume each reaction is carried out in an open container. For which reaction will ΔH = ΔE?                                                                (2006)

(a) 2CO(g)+ O2(g)→ 2CO2(g)

(b) H2(g)+ Br2(g)) →2HBr(g)

(c) C(s) + 2H2O(g) → 2H2(g)+ CO2(g)

(d) PCl5(g)   PCl3(g)+ Cl2(g)

23. (NEET 2013)

(a) z = x + y                               (b) x = y + z

(c) y = 2z – x                            (d) x = y – z

24. Standard enthalpy of vaporization  ΔvapH° for water at 100°C is 40.66 kJ mol–1. The internal energy of vaporization of water at 100°C (in kJ mol–1) is             (NEET 2013)

(a) +37.56                 (b) – 43.76

(c) + 43.76                (d) + 40.66