A type of emergency apparatus that can be used where oxygen may be limited or where the air might be poisoned is based on the following reaction in which CO2 produced by your own respiration reacts and O2 gas is produced. Calculate the mass of KO2 needed to produce 25 g of oxygen gas.
4 KO2(s) + 2 CO2(g) 2 K2CO3(s) + 3 O2 (g)