Answer:
A total of 25.6 kj of hear energy is added to a 5.18l sample of helium at .987atm The gas is allowed to expand against a fixed external pressure to a volume of 18.4l
A) calculate the work done on or by the helium gas units of joules, J.
B) what is the change in the helium a internal energy in units kilojoules, KJ?
A. Workdone by helium, W = -1.322KJ
B. Internal energy, DE = 24.278KJ
Step-by-step explanation:
Workdone can be defined as the force moving through a distance. For a gaseous system, when the volume of the gas expands, the system is losing energy. Therefore,
W = -P*DV
Where P is the pressure in pascal
DV is the change in volume in m3
DV = Vfinal - Vinitial
= 18.4 - 5.18
= 13.22L
W = -(0.987 * 13.22)
= -13.0481L.atm
Converting L.atm to joule,
= -13.0481 * 101.325
= -1322.099J
= -1.322KJ
If the system loses heat, Q the rection occurring is Exothermic.
Heat is the transfer of energy from one system to another.
Q = mcDT
Where m is the mass of the system
C is the specific heat capacity
Q = 25.6KJ
Internal energy is the summation of the heat supplied to a system and the workdone by the system
DE = Q + W
DE = 25.6 + (-1.322)
= 24.278KJ