Which of the following processes is reversible?
Transfer of heat by radiation
Electrical heating of a nichrome wire
Transfer of heat by conductor
Geothermal compression
In which case, a spontaneous reaction is possible at any temperature?
∆H –ve, ∆S +ve
∆H –ve, ∆S –ve
∆H +ve, ∆S +ve
None of these.
A monoatomic ideal gas undergoes a process in which the ratio of p to V at any instant is constant and equals to 1. What is the molar heat capacity of the gas?
4R / 2
3R / 2
5R / 2s
Zero
The value of log10 K for a reaction A B is
(Given, ∆rHo298 K = - 54.07 kJ mol -1
∆rSo298 k = 10 JK -1 mol -1
and R = 8.314 JK -1 mol -1
= 2.303 x 8.314 x 298
= 5705
5
10
95
100
One mole of a gas occupying 3 dm3 expands against constant external pressure of 1 atm to a volume of 13 dm3. The work done is
-10 atm dm3
-20 atm dm3
40 atm dm3
-50 atm dm3
The heat of sublimation of iodine is 24 cal g-1 at 50oC. If specific heat of solid iodine and its vapours are 0.055 and 0.031 cal g-1 respectively, the heat of sublimation of iodine at 100oC is
22.8 cal g-1
25.2 cal g-1
-22.8 cal g-1
-25.2 cal g-1
An ideal gas expands in volume from 10-3 m3 to 10-2 m3 at 300 K against a constant pressure of 105 Nm-2.
The work done is
800 kJ
900 kJ
270 kJ
-900 J
A gas present in a cylinder, fitted with a frictionless piston, expands against a constant pressure of 1 atm from a volume of 2 liter to a volume of 6 liter. In doing so, it absorbs 800 J heat from surroundings. The increase in internal energy of process is
305.85 J
394.95 J
405.83 J
-463.28 J
Spontaneous adsorption of a gas on solid surface is an exothermic process because
∆H increases for system
∆S increases for gas
∆S decreases for gas
∆G increases for gas.
When 1.8 g of steam at the normal boiling point of water is converted into water, at the same temperature, enthalpy and entropy changes respectively will be
[ Given ∆Hvap for water = 40.8kJ mol-1 ]
-8.12 kJ, 11.89JK -1
10.25kJ, 12.95JK -1
-4.08 kJ, -10.93 JK -1
10.93 kJ, 4.08 JK -1
