Originally.. Three moles of an ideal gas have an internal energy of 300 joules.
ID: 1689591 • Letter: O
Question
Originally.. Three moles of an ideal gas have an internal energy of 300 joules. The temperature of the gas is tripled as the pressure increases by a factor of 2. What is the final volume and internal energy of the gas?a) V_f = 1.5 V_i and E_int.f = 900 joules. b) V_f = 0.5 V_i and E_int.f = 450 joules. c) V_f = 2.5 V_i and E_int.f = 300 joules. d) V_f = V_i and E_int.f = 450 joules. e) V_f = 0.5 V_i and E_int.f = 900 joules. Worked this up many different way and didn't get anything close to the choices. Originally.. Three moles of an ideal gas have an internal energy of 300 joules. The temperature of the gas is tripled as the pressure increases by a factor of 2. What is the final volume and internal energy of the gas?
a) V_f = 1.5 V_i and E_int.f = 900 joules. b) V_f = 0.5 V_i and E_int.f = 450 joules. c) V_f = 2.5 V_i and E_int.f = 300 joules. d) V_f = V_i and E_int.f = 450 joules. e) V_f = 0.5 V_i and E_int.f = 900 joules. Worked this up many different way and didn't get anything close to the choices.
Explanation / Answer
Initial internal enenrgy U = 300 J Initial volume V =V Initila pressure P = P initial temp T = T final pressure P ' = P + 2P = 3P final temp T ' = 3T final volume V ' = ? from ideal gas equation P'V' / T ' = PV / T from this V ' = PVT' / TP' = V i.e., volume not charged option (d). only have Vf = Vi So, option (d0 is correct