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

Answer:

#"volume" = 0.03976L#

Explanation:

Recall the gas law

#PV = nRT#

#P = (nRT)/V#

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

#"735mmHg" /"760mmHg" = 0.96711atm#

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

Solve the equation

#0.9671053242406501atm = "30.6233n"/"0.05L"#

Multiply both sides with 0.05L

#\frac{30.6233n}{0.05L}*0.05=0.96711atm *0.05L#

#30.6233n=0.0483555#

#n = 30.6233/0.048355#

n = 0.00158moles

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

#"925mmHg"/"760mmHg" = 1.2171052631578947368421052631579atm#

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

#1.21711atm = 0.048384814/V#

#V = 0.048384814/"1.21711atm"#

#V = 0.03976L#

#"volume" = 0.03976L#