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

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

The 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

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

The entropy values (in JK^-1 mol^-1) of H_2(g) = 130.6, Cl_2(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

(1) + 540.3

(2) + 727.3

(3) – 166.9

(4) + 19.8

The ΔS for the vaporization 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        

The occurrence of a reaction is impossible if:

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

The enthalpy and entropy change for a chemical reaction are

–2.5 × 10³ cal and 7.4 cal deg^–1 respectively.  Predict the reaction at 298 K is

1. Spontaneous

2. Reversible

3. Irreversible

4. Non-spontaneous

Which of the following is true for the reaction $H_{2}O\left(l\right)\underset{}{\overset{}{\rightleftharpoons }}{H}_{2}O\left(g\right)$ at 100°C and 1 atmosphere

1. ΔE = 0

2. ΔH = 0

3. ΔH = ΔE

4. ΔH = TΔS

The enthalpy of vapourization water is 386 kJ. What is the entropy of water

(1) 0.5 kJ

(2) 1.03 kJ

(3) 1.5 kJ

(4) 22.05 kJ