Question 1

Multiple choiceEasy1 mark

A fixed amount of ideal gas changes between the two states shown. The labelled pressures are absolute; pp is a positive pressure and VV is a positive volume. Which expression gives TB/TAT_B/T_A

State AState BgasgasPA=2p, VA=VPB=3p, VB=2V
Show answer and explanation

Answer: A. For a fixed amount of ideal gas, PV/T=constantPV/T=\text{constant} so TB/TA=PBVB/(PAVA)T_B/T_A=P_BV_B/(P_AV_A) Substituting the values shown gives (3p)(2V)/[(2p)(V)]=3(3p)(2V)/[(2p)(V)]=3 the temperature ratio is dimensionless.
B: reverses the state ratio, giving TA/TB=1/3T_A/T_B=1/3
C: omits the volume ratio and uses pressure alone, giving 3/23/2
D: omits the pressure ratio and uses volume alone, giving 22
Remember: compare the products PVPV when finding temperature ratios for a fixed amount of ideal gas.

More B.3 Gas laws questions