<span>H2S H-S-H сера в соединении двухвалентна
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<span>2 H2S + 3 O2 = 2 H2O + 2 SO<span>2
</span></span><span>2 SO2 + O2 = 2 SO<span>3
</span></span><span>SO3 + H2O = H2SO<span>4
</span></span><span>2PH3 + 4O2 = P2O5 + 3H2O
</span><span>P2O5 + 3 H2O = 2 H3PO<span>4</span></span>
Ответ: O2 - ковалентная неполярная
СH3-CH2-OH + CuO -> CH3COH + Cu + H2O
CH3COH + Ag2O -> CH3COOH + 2Ag
2CH3COOH + 2Na -> 2CH3COONa + H2
CH3COONa + HCl -> CH3COOH + NaCl
S+O2=SO2
2SO2+O2=2SO3
SO3+H2O=H2SO4
H2SO4+Zn=ZnSO4+H2
ZnSO4+BaCl2=BaSO4+ZnCl2
BaSO4+2HNO3=Ba(NO3)2+H2SO4