A 40.3 gram sample of impure potassium nitrate (KNO3) was heated to complete decomposition according to the equation
2KNO3(s)----> 2KNO2 + O2
After the reaction was complete, the volume of the dry gas produce was 1 liters at 32 C and 867 torr. What was the percent KNO3 (101.1 g/mol) in the original sample? ( Assume that only the potassium nitrate had decomposed.)