- #1

wavingerwin

- 98

- 0

## Homework Statement

2 moles of gas at 300 K at 0.02 m

^{3}is expanded to twice the original volume at constant pressure, and then adiabatically until T = 300 K again.

assume monatomic gas. assume ideal.

determine the final volume

determine the heat supplied to the overall process

determine change in internal energy

## Homework Equations

[tex]PV = nRT[/tex]

[tex]TV^{\gamma-1} = TV^{\gamma-1}[/tex]

## The Attempt at a Solution

**State 1**

n = 2

V = 0.02

R = 8.31

T = 300

P = 249.3 kPa

**State 2**

P = 249.3

V = 0.04

T = 600 K

**State 3**

T = 300

monatomic therefore [tex]\gamma=5/3[/tex]

V = 0.061

so final volume is 0.061 m

^{3}

I am struggling to find the "heat supplied" to the system. Since from state 2 to 3 the process is adiabatic, Q = 0.

So the only heat transfer occur from state 1 to 2.

Would it just be equal to the work?

so Q = W = P(V

_{2}-V

_{1}) = 249300 x 0.02 = 5 kJ?

and so the change in internal energy must also be be 5 kJ?

thank you in advance.