A gas occupies 2 litre volume at STP. It is provided 300 joule heat so that its volume becomes 2.5 litre at 1 atm. Change in its internal energy will be

Question

A gas occupies 2 litre volume at STP. It is provided 300 joule heat so that its volume becomes 2.5 litre at 1 atm. Change in its internal energy will be (A) 239 joule (B) 205 joule (C) 249.34 joule (D) 220.37 joule

Tardigrade Admin · Accepted Answer

Work done =-P × d V=-1 ×(2.5-2.0) =-1 × 0.5=-0.5 text litre atm ∵ Work is carried out at constant P and thus irreversible. ∴ W =-0.5 × 101.325 J (1 L atm =101.235 J) =-50.66 J From first law of thermodynamics, q=Δ E-W, 300=Δ E-(-50.66) 300=Δ E+50.66, Δ E=249.34 J

Q. A gas occupies 2 litre volume at STP. It is provided 300 joule heat so that its volume becomes 2.5 litre at 1 atm. Change in its internal energy will be

239 joule

205 joule

249.34 joule

220.37 joule

Work done =−P×dV=−1×(2.5−2.0) =−1×0.5=−0.5 litre atm ∵ Work is carried out at constant P and thus irreversible. ∴W=−0.5×101.325J(1Latm=101.235J) =−50.66J From first law of thermodynamics, q=ΔE−W, 300=ΔE−(−50.66) 300=ΔE+50.66,ΔE=249.34J

Q. A gas occupies $2$ litre volume at STP. It is provided $300$ joule heat so that its volume becomes $2.5$ litre at $1$ atm. Change in its internal energy will be