ZnO
M(ZnO)=81 г/моль
w(Zn)=65/81*100%=80%
<span>w(O)=100%-80%=20%</span>
В)С3H8 пропан - верный ответ
А.
CuSO₄ + 2KOH = Cu(OH)₂ + K₂SO₄
Cu²⁺ + SO₄²⁻ + 2K⁺ + 2OH⁻ = Cu(OH)₂ + 2K⁺ + SO₄²⁻
Cu²⁺ + 2OH⁻ = Cu(OH)₂
Б.Cu(OH)₂ + 2HCl = CuCl₂ + 2H₂O
Cu(OH)₂ + 2H⁺ + 2Cl⁻ = Cu²⁺ + 2Cl⁻ + 2H₂O
Cu(OH)₂ + 2H⁺ = Cu²⁺ + 2H₂O
В.
Na₂CO₃ + BaCI₂ = 2NaCI + BaCO₃
2Na⁺ + CO₃²⁻ + Ba²⁺ + 2CI⁻ = 2Na⁺ + 2CI⁻ + BaCO₃
Ba²⁺ + CO₃²⁻ = BaCO₃
Г.NaOH + HNO₃ = NaNO₃ + H₂O
Na⁺ + OH⁻ + H⁺ + NO₃⁻ = Na⁺ + NO₃⁻ + H₂O
<span>OH</span>⁻ + H⁺ = H₂O
H2+Cl2=2HCl
2H3PO4+3MgO=Mg3(PO4)2+3H2O
3CaCl2+2K3PO4=Ca3(PO4)2+6KCl
2Zn+O2=2ZnO
3Ca + N2=Ca3N2
Ca+2HCl=CaCl2+H2
Mg+CuCl2=MgCl2+Cu
3Zn+2FeCl3=3ZnCl2+2Fe
2HNO3+Ca(OH)2=Ca(NO3)2+2H2O
2Al+3S=Al2S3
F2+2KBr=2KF+Br2
Fe2(SO4)3+6NaOH=2Fe(OH)3+3Na2SO4