Given that the gas constant R is 0.08206. Calculate the volume occupied by the oxygen gas at 20 C and 1 atm...

Given that the gas constant R is 0.08206. Calculate the volume occupied by the oxygen gas at 20 C and 1 atm when 0.300g of KCLO3 (molar mass 122.55g/mol) decomposes completely.

Use the ideal gas law, PV=nRT

In this case you want to convert 0.300g of KCLO3 to moles first because that is the units you need for n. To calculate that you simply divide 0.300g by 122.55g/mol:

.300/122.55=0.0024479804 moles

Next, convert your temperature from Celsius to Kelvin for use in the gas law. The equation for that is K=C+273, so...

K=20+273=293 K

Then just rearrange PV=nRT, and solve for V.

V=nRT/P

V=(0.0024479804 mol)(.08206)(293 K)/(1 atm)

V=0.058858213 L, but remember your sigfig's (in this case its 3 because its limited by your initial value of KCLO3)

V=.0589 L

I hope that's the answer. Otherwise it would be embarrassing since I am a chemistry major. LOL