# Homework Help: Cylinder volume calculation

1. Jun 4, 2013

### marcio

1. The problem statement, all variables and given/known data
An ideal gas is stored in a cylinder whose volume is unknown. Part of this gas is transfered to another cylinder whose volume is 300 cm3 and pressure is 790 mmHg. The mass loss caused the pressure in the first cylinder to decrease from 650 to 630 mmHg. Considering that all measurements were taken at constant temperature, calculate the volume of the cylinder.

2. Relevant equations
PV=nRT
PV=k

I just can't get it started.

2. Jun 4, 2013

### Staff: Mentor

Let n0 represent the number of moles of gas originally in the cylinder, and let n0-Δn be the number of moles remaining after part of the mass was transferred to the other cylinder. How many moles were transferred to the other cylinder. Let V equal to the volume of the cylinder of interest. Write the ideal gas equation for the conditions in the cylinder of interest both before the transfer of mass and after the transfer of mass. Also write the ideal gas equation for the conditions in the cylinder to which the mass was transferred.

Chet

3. Jun 5, 2013

### marcio

The start I needed exactly. It seems simple after you get the 'hint'.

Thank you very much.