To solve this problem, we establish the general energy balance:
ΔE = ΔU + ΔKE + ΔPE
ΔE = Q + W
Q + W = ΔU + ΔKE + ΔPE
In this case, ΔKE and ΔPE are both zero or negligible.
Given:
m = 33.0 grams of CO2
Tsub = 77 K
P = 1 atm
ΔE = Q + W
ΔE = mCpΔT + ΔPV
solve for mCpΔT, find the value of Cp for CO2, then solve for Q. Next, solve for W using the ideal gas law. Add the two values and that will be the value of the delta E.