KNO3=39+14+48=101г/моль  

w(K)= 39 /101*100=38.6%  

W(N)=14/101*100=13.9%  

W(O)= 48/101*100=47.5%  

KOH2=39+16+2=57г/моль

W(К)=39/101*100=38.6%  

W(O)=16/101*100=16.2%

W(H)= 2/101*100=2%  

SO2=32+32=64г/моль

W(S)=32/101*100=32%  

W(O)=32/101*100=32%

NH3=14+3=17г/моль

W(N)=14/101*100=13.9%  

W(H)=3/101*100=3%

Na2O= 46+16=62г/моль  

W(Na)=46/62*101=74.2%  

W(O)=16/101*100=15.85%