One mole of an ideal gas is allowed to expand freely and adiabatically into vacuum until its volume has doubled. A statement which is not true concerning this expression is [Pb. PMT 1998]

(1) ΔH = 0

(2) ΔS = 0

(3) ΔE = 0

(4) W = 0

Concept Questions :-

First Law of Thermodynamics
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Difficulty Level:

At 27°C, one mole of an ideal gas is compressed isothermally and reversibly from a pressure of 2 atm to 10 atm. The values of ΔE and q are (R = 2) [BHU 2001]

(1) 0, – 965.84 cal

(2) – 965.84 cal, + 965.84 cal

(3) + 865.58 cal, – 865.58 cal

(4) – 865.58 cal, – 865.58 cal

Concept Questions :-

First Law of Thermodynamics
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Difficulty Level:

ΔE° of combustion of isobutylene is –X kJ mol–1. The value of ΔH° is [DCE 2004]

(1) = ΔE°

(2) > ΔE°

(3) = 0

(4) < ΔE°

Concept Questions :-

Thermochemistry
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Difficulty Level:

An ideal gas expands in volume from 1 × 10–3 m3 to 1 × 10–2 m3 at 300 K against a constant pressure of 1 × 105 Nm–2. The work done is [AIEEE 2004]

(1) 270 kJ

(2) –900 kJ

(3) –900 J

(4) 900 kJ

Concept Questions :-

First Law of Thermodynamics
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Difficulty Level:

The spontaneous flow of heat is always

(1) From low to high pressure

(2) From high to high pressure

(3) Unidirectional from lower temperature to higher temperature

(4) Unidirectional from the higher to lower temperature

Concept Questions :-

Spontaneity and Entropy
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Difficulty Level:

Mixing of non-reacting gases is generally accompanied by

(1) Decrease in entropy

(2) Increase in entropy

(3) Change in enthalpy

(4) Change in free energy

Concept Questions :-

Enthalpy and It's Type
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Difficulty Level:

An irreversible process occuring isothermally in an isolated system leads to

(1) Zero entropy

(2) An increase in the total entropy of the system

(3) A decrease in the total entropy of the system

(4) None of these

Concept Questions :-

Spontaneity and Entropy
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Difficulty Level:

The entropy values (in JK-1 mol-1) of H2(g) = 130.6, Cl2(g) = 223.0 and HCl(g) = 186.7 at 298 K and 1 atm pressure. Then entropy change for the reaction ${\mathrm{H}}_{2\left(\mathrm{g}\right)}+{\mathrm{Cl}}_{2\left(\mathrm{g}\right)}\to 2{\mathrm{HCl}}_{\left(\mathrm{g}\right)}$ is [BHU 2005]

(1) + 540.3

(2) + 727.3

(3) – 166.9

(4) + 19.8

Concept Questions :-

Spontaneity and Entropy
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The ΔS for the vaporisation of 1 mol of water is 88.3 J/mole K. The value of ΔS for the condensation of 1 mol of vapour will be

(1) 88.3 J/mol K

(2) (88.3)2 J/mol K

(3) – 88.3 J/mol K

(4) $\frac{1}{88.3}$ J/mol K

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Difficulty Level:

The occurrence of a reaction is impossible if [AIIMS 1982, 91; MP PET 1997; MP PMT 1999; DPMT 2002]

(1) ΔH is +ve ; ΔS is also + ve but ΔH < TΔS

(2) ΔH is – ve ; ΔS is also – ve but ΔH > TΔS

(3) ΔH is – ve ; ΔS is + ve

(4) ΔH is + ve ; ΔS is – ve

Concept Questions :-

Spontaneity and Entropy