Pb(CH₃COO)₂+H₂S = PbS↓ + 2CH₃COOH
Pb²⁺ + 2CH₃COO⁻ + 2H⁺ + S²⁻ = PbS↓ + 2CH₃COO⁻ + 2H⁺
Pb²⁺ + S²⁻ = PbS↓
<span>Cu + 2H₂SO₄ (конц.) +t = CuSO₄+ SO₂↑ + 2H₂O</span>
1) С2H5OH->CH2=CH2+H2O(T>140,cat- H2SO4)
2)CH2=CH2+h2->CH3-CH3(Ni)
3)CH3-CH3+Br2->C2H5Br+HBr(hv)