For the reaction A + B → C + D + q (kJ/mol), entropy change is positive. The reaction will be

1. Possible only at high temperature

2. Possible only at low temperature

3. Not possible at any temperature

4. Possible at any temperature

For the reaction, $2C{}^{}\to C{}^{}$, the value of ∆H and ∆S  are respectively -

1. $∆\mathrm{H}=0$ $,$ $∆\mathrm{S}=-\mathrm{ve}$

2. $∆\mathrm{H}=0$ $,$ $∆\mathrm{S}=0$

3. $∆\mathrm{H}=$ $-\mathrm{ve}$ $,$ $∆\mathrm{S}$ $=$ $-\mathrm{ve}$

4. $∆\mathrm{H}=$ $+\mathrm{ve}$ $,$ $∆\mathrm{S}=$ $+\mathrm{ve}$

For the reaction at 298 K,

2A + B → C

ΔH = 400 kJ mol⁻¹ and ΔS = 0.2 kJ K⁻¹ mol⁻¹. The reaction will become spontaneous at-

1. 1500 K
2. 2000 K
3. 100 K
4. 1900K

The entropy change in the surroundings when 1.00 mol of H₂O_(l) is formed under standard conditions is-

∆_fH^θ = –286 kJ mol^–1 

1. 952.5 J mol^-1

2. $979.7$ $\mathrm{J}$ ${\mathrm{mol}}^{-1}$

3. $949.7$ $\mathrm{J}$ ${\mathrm{mol}}^{-1}$

4. $959.7$ $\mathrm{J}$ ${\mathrm{mol}}^{-1}$