The correct option is B −2.7 kcal
At STP, 160 g of O2 or 5 mole of O2 will occupy 22.4×5=112 L volume.
Now, if the volume is doubled, it means V2 = 224 L
So, (V2−V1) =224−112=112 L
At STP = P = 1 atm
Now,putting values
w=−P×(V2−V1)=−1×112 L atm=−112 Latm
since,
1 Latm=101.3J
so,
−112Latm=−112×101.3 J =
w=−11345.6 J
Since, 1 cal = 4.18 J
w=11345.64.18
=−2711.7 cal =−2.7 kcal