Mr(H2SO4) = 1*2 + 32 + 16*4 = 98
W(O) = Ar(O) * n / Mr(H2SO4) *100% = 16*4 / 98 *100% = 65,3%
2Сa + O₂ = 2CaO
CaO + H₂O = Ca(OH)₂
Ca(OH)₂ + 2HBr = CaBr₂ + 2H₂O
CaBr₂ + Na₂CO₃ = CaCO₃ + 2NaBr
СH3COH+Ag2O=CH3COOH+2Ag;
Mr(CH3COH)=44г;
Mr(2Ag)=108г*2=216г;
44г CH3COH ----216г Ag;
28г CH3COH ---xг Ag;
x=28г*216г/44г=137.45г Ag