1. It's all NA2O2.

If heated in a closed space, if there is no air, then NA2O2 is very stable (not to say that it is impossible to decompose, but this temperature is relatively high, so middle school generally does not consider its decomposition), and it will not decompose, and the product is still NA2O2.

2. They are all sodium bicarbonate

It is decomposed into CO2 and Na2CO3H2O by heating.

3. Both.

There are several situations here. As we all know, NA2O2 will react with H2O or CO2, but which "priority" will it react with? If it reacts with water, NAOH and O2 will be generated, but NAOH will immediately react with CO2, and at the same time, NA2CO3 and the same amount of water will be generated, so generally speaking, NA2O2 will react with CO2 first, and then react with water until it completely reacts with CO2 (not to say that it does not react with water at all, but generally speaking). Therefore, the product at this time depends on the ratio of NA2O2 to NAHCO3. When the proportion of sodium bicarbonate is low, Na2O 2 will continue to react with H2O after the reaction with CO2, while when the proportion of sodium bicarbonate is high, Na2O 2 will react with CO2. The specific mass ratio is not calculated here. The landlord can calculate, so it is easy to write a formula.