1)Cr<span> + </span><span>HCl</span><span> = </span>CrCl2<span> + </span>H2↑
<span><span>Cr2+</span><span>21</span></span><span>2H+ + Cr = 2H + Cr<span>2+
</span></span>2)<span>4HNO3(конц.)</span><span> + </span>18HCl<span>(конц.)</span><span> + </span><span>3Pt</span><span> = </span>3H2<span>[PtCl6]</span><span> + </span>4NO↑<span> + </span>8H2O
4NO3<span> + </span>16H+ 3Pt<span> + </span>18Cl−<span> = </span>4NO<span> + </span>8H2O<span> + </span>3PtCl6
3)Ag2O + H2 = 2Ag + H2O
Ag + H = Ag + H
<span>4)?не знаю..
5)2H3PO4(разб.) + 3Mg = Mg3(PO4)2↓ + 3H2↑
2H+ + Mg = H2 + Mg+
6)PbO + H2 = Pb + H2O
Pb+ 2H = Pb + 2H</span>
V(He)=n(He)*Vm=10*22.4=224 (л)
Ответ: 224 л.
MgO + 2HCl = MgCl2 + H2
Cu(OH)2 + 2HCl = CuCl2 + 2H2O
Zn + 2HCl = ZnCl2 + H2
Na2CO3 + 2HCl = 2NaCl + H2O + CO2