Question- When solid potassium nitrate, KNO3, is heated under certain conditions, it partially decomposes to form another solid, potassium nitrite (KN)2) and gaseous oxygen, O2, according to the following equation

2KNO3 ------> 2KNO2 + O2

In an experiment when a 2.500g sample of KNO3 was heated, the resulting solid mixture consisting of unreacted KNO3 and KNO2 formed weighed 2.210g

Part a) What is the mass in grams of O2 gas that was produced in the reaction as described above?

Part b) What is the percent yield of O2 produced in the reaction?

Part c) Of the resulting 2.210g mixture of KNO3 and KNO2 recovered at the end of the reaction, how much was unreacted KNO3 and how much was KNO2?

I just need a general explanation of it please- Thanks!