S+H2=H2S
H2S=H2+S
S +Fe=FeS
<span>FeS + 2HCl(разб.) = FeCl2 + H2<span>S
</span></span><span>O3 + H2S(газ) = SO2 + H2O
2SO2+O2=2SO3
SO3+H2O=H2SO4</span>
2Ca+O2=2CaO , CaO+2NaOH=Ca(OH)2+Na2O , Ca(OH)2+2NaCl =CaCl2+2NaOH
................................................................................Гелий
Они должны содержать массу, равную35грамм
2HNO₃ + Cu(OH)₂ = Cu(NO₃)₂ + 2H₂O1)Cu²⁺ + 2OH⁻ + 2H⁺ + 2NO₃⁻ = Cu²⁺ +2NO₃⁻ + 2H₂0
2)OH⁻ + H⁺ = H₂<span>0
</span>
<span>AgNO</span>₃ + NaCl = NaNO₃ + AgCl↓ 1)Ag⁺ + NO₃⁻ + Na⁺ + Cl⁻ = Na⁺ + NO₃⁻ + AgCl↓ <span>2)Ag</span><span>⁺</span><span> </span><span>+</span><span> </span><span>Cl</span><span>⁻</span><span> </span><span>=</span><span> </span><span>Ag</span><span>Cl</span><span>↓</span><span>
</span>
Na₂SO₃ +
2H₂SO₄ = 2NaHSO₄ + SO₂↑ + H₂O
1)2Na⁺ +
SO₃²⁻ + 4H⁺ + 2SO₄²⁻ = 2Na⁺ + 2HSO₄⁻ + SO2↑ + H2O
<span>2)SO</span><span>₃</span><span>²</span><span>⁻</span><span> + 4H</span><span>⁺</span><span> + 2SO</span><span>₄</span><span>²</span><span>⁻</span><span> = 2HSO</span><span>₄</span><span>⁻</span><span> + SO</span>₂<span>↑ + H</span>₂<span>O</span>