How many grams of KO2 are needed to produce 370.0 L of O2 at 20.0 degrees Celsius and 1.00 atm?

Question

4KO2(s) +2CO2(g) --> 2K2CO3(s)+ 3O2(g)

Answer 1

mols O2; use PV = nRT (remember T must be in kelvin) and solve for n = number of mols.
Using the coefficients in the balanced equation, convert mols O2 to mols KO2.

Now convert mols KO2 to grams.
mols = grams/molar mass.