TS EAMCET 10-Sep-2020 Shift 2 Solved Paper

∵ Given, Molar heat capacity for oxygen
‌‌=20.8Jmol−1K−1
Q‌‌=nC∆T
where, Q= value of ∆U in J
n= number of moles (=1)
C= heat capacity
∆T= temperature
Q=1×20.8×60
Thus, ∆T=(−)20 to (+)40=60∘C
Hence, for one mole of oxygen,
value of ∆U=60×20.8=1248J
Hence, option (d) is the correct answer.