Heat and Work
Trending Questions
Q. Closed systems can exchange which of the following with the surroundings?
- Heat
- Matter
- Heat and Matter
- Neither heat nor matter
Q. When a system is taken from A to C through path ABC, 10 J of heat flows to the system and 4 J of work is done by the system.How much heat flows into the system in path ADC, if the work done by the system is 3 J?
![](https://s3-us-west-2.amazonaws.com/infinitestudent-images/ckeditor_assets/pictures/605496/original_15.black.png)
![](https://s3-us-west-2.amazonaws.com/infinitestudent-images/ckeditor_assets/pictures/605496/original_15.black.png)
Q. In the cyclic process shown in P-V diagram, the magnitude of the work done is
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/882252/original_26.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/882252/original_26.png)
- π(P2−P12)2
- π(V2−V12)2
- π4(P2−P1)(V2−V1)
- π(V2−V1)2
Q. Assign the sign of work done (based on SI convention) in the following chemical changes taking place against the external atmospheric pressure:
(I) N2(g)+3H2(g)→2NH3(g)
(II) NH4HS(s)→NH3(g)+H2S(g)
(III) C(s)+CO2(g)→2CO(g)
(IV) C2H6(g)+3.5O2(g)→2CO2(g)+3H2O(l)
(I) N2(g)+3H2(g)→2NH3(g)
(II) NH4HS(s)→NH3(g)+H2S(g)
(III) C(s)+CO2(g)→2CO(g)
(IV) C2H6(g)+3.5O2(g)→2CO2(g)+3H2O(l)
- I II III IV
+ − − + - I II III IV
+ + − − - I II III IV
− + 0 + - I II III IV
+ − 0 −
Q. An ideal monatomic gas is taken round the cycle ABCD as shown in the figure. The work done during the cycle is:
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/826585/original_Thermo_2.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/826585/original_Thermo_2.png)
- pV
- 2pV
- 12pV
- zero
Q. Which of the following processes is an iso-entropic process?
- Isothermal process
- Adiabatic process
- Isobaric process
- Isochoric process
Q. A thermodynamic system goes from states (i) P1, V to 2P1, V and
(ii) P, V1 to P, 2V1
The work done in the two cases respectively is:
(ii) P, V1 to P, 2V1
The work done in the two cases respectively is:
- Zero, Zero
- Zero, −PV1
- −PV1, Zero
- −PV1, −P1V1
Q. An ideal monatomic gas is taken round the cycle ABCD as shown in the figure. The work done during the cycle is:
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/826585/original_Thermo_2.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/826585/original_Thermo_2.png)
- pV
- 2pV
- 12pV
- zero
Q. In the figure , the net amount of work done will be:
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/824962/original_Thermo_4.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/824962/original_Thermo_4.png)
- Positive
- Negative
- Zero
- Infinity
Q. A heating coil is immersed in a 100 g sample of H2O(l) at 1 atm and 100∘C in a closed vessel. In this heating process, 60% of the liquid is converted in to gaseous form at constant pressure of 1 bar. Densities of liquid and gaseous water under these condition are 1000kg/m3, 0.60kg/m3 respectively. magnitude of the work done for the process is :
- 4997 J
- 3970 J
- 9994 J
- None of these
Q. 1 mole of an ideal gas, initially at 400 K and 10 atm is first expanded at constant pressure till the volume is doubled. Then the gas is made to undergo an isochoric process, in which its temperature is found to decrease. In the last step, the gas was compressed reversibly and adiabatically to its initial state. Determine the net work involved in this cyclic process (in terms of R). Given, CV for gas =1.5 R, (4)−1/3=0.63. If |W|=2 R×z, what is the value of z?