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 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

The entropy changed involved in the conversion of 1 mole of liquid water at 373 K to vapour at the same temperature will be $[\Delta H_{\text{vap}}=2.257kJ/gm]$ [MP PET 2002]

(1) 0.119 kJ

(2) 0.109 kJ

(3) 0.129 kJ

(4) 0.120 kJ

When a liquid boils, there is [JIPMER 2002]

(1) An increase in entropy

(2) A decrease in entropy

(3) An increase in heat of vaporization

(4) An increase in free energy

For a carnot engine, the source is at 500 K and the sink at 300 K. What is efficiency of this engine

(1) 0.2

(2) 0.4

(3) 0.6

(4) 0.3

A solution of 500 ml of 0.2 M KOH and 500 ml of 0.2 M HCl is mixed and stirred; the rise in temperature is T₁. The experiment is repeated using 250 ml each of solution, the temperature raised is T₂. Which of the following is true

(1) T₁ = T₂

(2) T₁ = 2T₂

(3) T₁ = 4T₂

(4) T₂ = 9T₁

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 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 work done in ergs for the reversible expansion of one mole of an ideal gas from a volume of 10 liters to 20 liters at 25°C is -

1. $-2.303\times 298\times 0.082$ $\log$ $2$

2. $-298\times {10}^7\times 8.31\times 2.303$ $\log$ $2$

3. $2.303\times 298\times 0.082$ $\log$ $0.5$

4. $-8.31\times {10}^7\times 298-2.303$ $\log$ $0.5$

Which of the following is not a state function 

(1) Internal energy

(2) Enthalpy

(3) Work

(4) Entropy