If 1.000g of (potash) K2CO3 reacts with H2SO4 to produce 145 mL of CO2 gas at STP, what is percentage of Potassium Carbonate in the marble sample?
H2SO4 + K2CO3 ==> CO2 + H2O + K2SO4
Convert 145 mL CO2 at STP to moles CO2 (remember 1 mole of ANY gas occupies 22.4L at STP), then use the coefficients in the balanced equation to convert moles CO2 to moles K2CO3, then grams K2CO3.
%K2CO3 = (grams K2CO3/1.00g sample)*100 = ??