If the pressure of 50.0 mL of oxygen gas at 100°C increases from 735 mm Hg to 925 mm Hg, what is the final volume? Assume the temperature remains constant.

1 Answer
Feb 16, 2017

volume=0.03976L

Explanation:

Recall the gas law

PV=nRT

P=nRTV

Our question
If the pressure of 50.0 mL of oxygen gas at 100°C increases from 735 mm Hg to 925 mm Hg, what is the final volume? Assume the temperature remains constant.
This means

735mmHg={n * 0.0821L * (100C + 273K )}50.0mL 1000ml

mmHg must be converted in atm , celsius to kelvin and ml to Litres

=1 atm = 760mmHg

735mmHg760mmHg=0.96711atm

0.9671053242406501atm = n * 0.0821L * 373K/0.05L

Solve the equation

0.9671053242406501atm=30.6233n0.05L

Multiply both sides with 0.05L

30.6233n0.05L0.05=0.96711atm0.05L

30.6233n=0.0483555

n=30.62330.048355

n = 0.00158moles

So lets now calculate volume when we know n.
n is constant in both the equation.

925mmHg760mmHg=1.2171052631578947368421052631579atm

1.21711atm=(0.00158 * 0.0821L * 373K)V

1.21711atm=0.048384814V

V=0.0483848141.21711atm

V=0.03976L

volume=0.03976L