Chemistry Question Bank

A system undergoes a 2-step process. In step 1, 15 J of work is done on the system as its internal energy increases by a total of 30 J. In step 2, at constant volume, the system decreases its internal energy by 20 J. …

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)

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 (Odisha NEET 2019)

In which case change in entropy is negative? (NEET 2019)

Assertion: Addition of Q and w gives ΔU. Reason: Addition of two path functions cannot give state function.

For the reaction, 2Cl(g) → Cl₂(g), the correct option is (NEET 2020)

For the reaction of one mole of zinc dust with one mole of sulphuric acid in a bomb calorimeter, U and w correspond to

Consider the following liquid-vapour equilibrium. Liquid ⇌ Vapour Which of the following relations is correct? (NEET-I 2016) (a) v H dln P dT T (b) v H d ln P dT RT (c) v H dln G dT RT (d) v H d ln P dT RT

For a sample of perfect gas when its pressure is changed isothermally from pi to pf, the entropy change is given by. (NEET-II 2016)

The heat of combustion 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 (2015)

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 U of the gas in joul…

The enthalpy of fusion of water is 1.435 kcal/mol. The molar entropy change for the melting of ice at 0°C is (2012)

In which of the following reactions, standard reaction entropy change (∆S°) is positive and standard Gibbs energy change (∆G°) decreases sharply with increasing temperature? (2012)

Three thermochemical equations are given below: (i) C(graphite) + O₂(g) → CO₂(g); ∆rH° = x kJ mol–1 (ii) C(graphite) + ½O₂(g) → CO(g); ∆rH° = y kJ mol–1 (iii) CO(g) + ½O₂(g) → CO₂(g); ∆rH° = z kJ mol–1 Based on the ab…

When 5 litres of a gas mixture of methane and propane is perfectly combusted at 0°C and 1 atmosphere, 16 litres of oxygen at the same temperature and pressure is consumed. The amount of heat released from this combust…

Standard enthalpy of vaporisation o vap H for water at 100°C is 40.66 kJ mol–1. The internal energy of vaporisation of water at 100°C (in kJ mol–1) is (2012)

For the reaction, X2O₄(l) → 2XO₂(g) ∆U = 2.1 kcal, ∆S = 20 cal K–1 at 300 K Hence, ∆G is (2014)

For a given reaction, ∆H = 35.5 kJ mol–1 and ∆S = 83.6 J K–1 mol–1. The reaction is spontaneous at (Assume that ∆H and ∆S do not vary with temperature.) (NEET 2017)

Which law states that entropy of all pure crystalline solids is zero at absolute zero?

Which of the following statements is not correct?

The respective examples of extensive and intensive properties are

Entropy is a measure of

The standard free energy change  G  is related to K (equilibrium constant) as

The bond dissociation energies of X2, Y₂ and XY are in the ratio of 1 : 0.5 : 1. ∆H for the formation of XY is – 200 kJ mol–1. The bond dissociation energy of X2 will be (NEET 2018)

Assertion: A reaction which is spontaneous and accompanied by decrease of randomness must be exothermic. Reason: All exothermic reactions are accompanied by decrease in randomness.