nomer 8 ) 4K + O2 ---> 2K2O

Mr(4K) = 156 gr/moli

Mr (2K2O) = 188 gr/moli

m(K2O) = 7.8 * 188/156 = 9.4 gr

nomer 9 ) KClO4 = KCl + 2O2

Mr(KClO4) = 123.5 gr/moli

V(O2) = 24.5 * 44.8/ 123.5 = 88.8 litra