How Do You Calculate Work When Compressing Gas?

[jybe]

Homework Statement

What is w when a gas is compressed from 42.1 L to 25.1 L using a constant external pressure of 739 Torr? Remember to include a "+" or "−" sign as appropriate.

Homework Equations

W = -P(dV)

The Attempt at a Solution

Pressure = (739 Torr / 760 Torr)*(101.325 kPa)

W = -((739 Torr / 760 Torr)*(101.325 kPa))*(-17 L)

W = +1674.9289 J (by the convention that when the system is compressed, work is positive)

Is this correct?

Also, it says "Enter your answer in acceptable SI units, accurate to 3 significant figures. Use an acceptable SI symbol for units." Would I enter it as 1.68 KJ?

 

[Chestermiller]

Homework Statement

What is w when a gas is compressed from 42.1 L to 25.1 L using a constant external pressure of 739 Torr? Remember to include a "+" or "−" sign as appropriate.

Homework Equations

W = -P(dV)

The Attempt at a Solution

Pressure = (739 Torr / 760 Torr)*(101.325 kPa)

W = -((739 Torr / 760 Torr)*(101.325 kPa))*(-17 L)

W = +1674.9289 J (by the convention that when the system is compressed, work is positive)

Is this correct?

Also, it says "Enter your answer in acceptable SI units, accurate to 3 significant figures. Use an acceptable SI symbol for units." Would I enter it as 1.68 KJ?

To 3 significant figures, you would enter it as 1.67 kJ.