Three moles of an ideal gas expanded spontaneously into vacuum. The work done will be:
1. 3 Joules
2. 9 Joules
3. Zero
4. Infinite
The following two reactions are known
The value of H for the following reaction
is:
1. -43.3 kJ
2. -10.3 kJ
3. +6.2 kJ
4. +10.3 kJ
Match List – I (Equations) with List – II (Type of processes) and select the correct option.
List – I | List – II | ||
Equation | Type of processes | ||
(a) | Kp > Q | (i) | Non-spontaneous |
(b) | ∆Gº < RT ln Q | (ii) | Equilibrium |
(c) | Kp = Q | (iii) | Spontaneous and endothermic |
(d) | T > \(\frac{\Delta H}{\Delta S}\) | (iv) | Spontaneous |
Options: | (a) | (b) | (c) | (d) |
1. | (iii) | (iv) | (ii) | (i) |
2. | (iv) | (i) | (ii) | (iii) |
3. | (ii) | (i) | (iv) | (iii) |
4. | (i) | (ii) | (iii) | (iv) |
For vaporization of water at 1 atmospheric pressure, the values of ∆H and ∆S are 40.63 kJ mol–1 and 108.8 JK–1 mol–1, respectively. The temperature when Gibbs energy change (∆G) for this transformation will be zero, is:
1. 393.4 K
2. 373.4 K
3. 293.4 K
4. 273.4 K
Consider the following processes:
∆H (kJ/mol)
½ A → B + 150
3B → 2C + D –125
E + A → 2D +350
For B + D → E + 2C, ∆H will be-
1. 325 kJ/mol
2. 525 kJ/mol
3. –175 kJ.mol
4. –325 kJ/mol
A reaction occurs spontaneously if:
1. T∆S > ∆H and ∆H is +ve and ∆S are –ve
2. T∆S = ∆H and both ∆H and ∆S are +ve
3. T∆S < ∆H and both ∆H and ∆S are +ve
4. T∆S > ∆H and both ∆H and ∆S are +ve
Which of the following pairs of chemical reactions is certain to result in a spontaneous reaction:
1. Endothermic and decreasing disorder
2. Exothermic and increasing disorder
3. Endothermic and increasing disorder
4. Exothermic and decreasing disorder
Identify the correct statement regarding entropy:
1. | At absolute zero of temperature, the entropy of all crystalline substances is taken to be zero |
2. | At absolute zero of temperature, the entropy of a perfectly crystalline substance is +ve |
3. | At absolute zero of temperature, the entropy of a perfectly crystalline substance is taken to be zero |
4. | At 0 °C , the entropy of a perfectly crystalline substance is taken to be zero |
One mole of an ideal gas at 300 K is expanded isothermally from an initial volume of 1 litre to 10 litres. The ∆E for this process is:
(R = 2 cal. )
1. 1381.1 cal.
2. Zero
3. 163.7 cal.
4. 9 lit. atm
If the bond energies of H–H, Br – Br, and H –Br are 433, 192, and 364 kJ mol–1 respectively, the ∆Hº for the reaction H2(g) + Br2(g) → 2HBr(g) will be:
1. +103 kJ
2. +261kJ
3. –103 kJ
4. –261 kJ