500г-100=400-20%
400г*20%=80г
400г+100=500г
80/500=0.16=16%
2)500г-100=400-16%
400г*0,16=64г
400+100=500
64/500=0, 128=12%.8%
2 )мч(NH4 NO3) = 14+1*4 14+16*3= 28 62
1) мч(MqCo3) = 24+59*3= 201
1) Na2O + Ca(OH)2 → CaO + 2NaOH
Na2O + Ca + 2OH → CaO + 2Na + 2OH
Na2O + Ca → CaO + 2 Na
2) 3NaOH + H3PO4 → Na3PO4 + 3H2O
3Na + 3OH + 3H + PO4 → 3Na + PO4 + 3H2O
3H + 3OH → 3H2O