Question

a gas occupies 2 litre at s.t.p .It is provided 58.63 joule heat so that it's volume becomes 2.5 litre at 1 atm.calculate change in its internal energy
please give explanation also​

Answer 1

Hi,

Answer:

Change in the internal energy = 8 J

Explanation:

Given data:  

The initial volume of gas, Vi = 2 L

Heat provided, Q = 58.63 J

The final volume, Vf = 2.5 L  

Final pressure, Pf = 1 atm  

To find: Change in its internal energy

We know, that the work is done at constant pressure and thus is irreversible.

∴ The work done,  

W = - P∆V = - 1 * (2.5 - 2) = - 0.5 L atm = -0.5 * 101.3 J = 50.631 J   [ ∵ 1 L atm = 101.3 J]

Using First Law of Thermodynamics,  

Q = ∆U – W

Where  ∆U = change in the internal energy

Or, ∆U = q + W = 58.63 + (-50.631) = 7.99 J ≈ 8 J

Hope this is helpful!!!!!