Which of the following correctly explains why a gas heats up when compressed rapidly in a thermally insulated cylinder?
A.
Compression reduces molecular mass
B.
The gas molecules absorb infrared radiation from the walls
C.
Heat flows in from the hot piston
D.
The piston moves towards the gas molecules; each molecule colliding with the moving piston rebounds faster โ gaining kinetic energy, raising temperature
D. The piston moves towards the gas molecules; each molecule colliding with the moving piston rebounds faster โ gaining kinetic energy, raising temperature
8.
In NCERT Exercise 11.5, a gas is taken adiabatically from state A to B with work done ON the system = 22.3 J. The change in internal energy ฮU is:
A.
ฮU = 0 (adiabatic means no energy change)
B.
ฮU = +22.3 J (work done on gas increases internal energy)
D. ฮQ = ฮW < 0 (heat released by gas to reservoir during compression)
11.
For isothermal compression of 1 mole of ideal gas at T = 300 K from Vโ to Vโ/2 (volume halved). Work done BY gas is: (R = 8.3 J/molยทK, ln 2 = 0.693)
For isothermal compression of n moles of ideal gas at temperature T, if the volume is reduced to one-quarter (Vโ = Vโ/4), the work done BY the gas is:
