A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy Δ U of the gas in joules will be

Question

A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy Δ U of the gas in joules will be (A) - 500 J (B) - 505 J (C) + 505 J (D) 1136.25 J

Tardigrade Admin · Accepted Answer

As q = 0 so using I law of Thermodynamics. Δ U=-p.Δ V =-2.5(.4.5-2.5.)=-5 lit atm =-5× 101.3=-506.5 Joule =-505 J

Q. A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy $Δ U$ of the gas in joules will be

- 500 J

- 505 J

+ 505 J

1136.25 J

As q = 0 so using I law of Thermodynamics.
$Δ U = - p .Δ V$
$= - 2.5 (4.5 - 2.5) = - 5$ lit atm
$= - 5 \times 101.3 = - 506.5$ Joule
$= - 505$ J

Q. A gas is allowed to expand in a well insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy ΔU of the gas in joules will be