<span>1) 2Cr + KClO3 = Cr2O3 + KCl;
</span><span>2) N2H4 + 2H2O2 = N2 + 4H2O;
</span><span>3) 4CaO + 2Cr2O3 + 3O2 = 4CaCrO4;
</span><span>4) 2KNO3 + 3C + S = N2 + 3CO2 + K2S;
</span><span>5) FeCl2 + 6KCN = K4[Fe(CN)6] + 2KCl.</span>
В2
1В
2Б
3А
4Г
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1) Zn + 2HCl = ZnCl₂ + H₂↑
2) ZnCl₂ + 2KOH = Zn(OH)₂↓ + 2KCl
Zn²⁺ + 2Cl⁻ + 2K⁺ + 2OH⁻ = Zn(OH)₂↓ + 2K⁺ + 2Cl⁻
Zn²⁺ + 2OH⁻ = Zn(OH)₂↓
3) Zn(OH)₂ + 2NaOH = Na₂ZnO₂ + 2H₂O
n = N/N.a.
N.a. = 6.02 * 10^23
a)n(S) = 6*10^22/6.02*10^23 = 0.0993367 = 0.1 (моль)
б)n(CO2) = 3*10^25/6.02*10^23 = 49.8 (моль).