<span><span>2<span>H2O</span></span> → <span>2 <span>H2</span></span>+<span>O2
</span></span><span><span>5<span>O2</span></span>+<span>4P</span> → <span>2<span>P2O5 </span></span></span>
<span><span>P2O5</span>+<span>3<span>H2O</span></span> → <span>2<span>H3PO<span>4
</span></span></span></span>
.............
w=5/35=0.143 14.3%
2H₂+O₂=2H₂O.
1.n(H₂)=m/M=8/2=4 моль
2.n(H₂O)=n(H₂)=4 моль
3.m(H₂O)=n·M=4·18=72 г.
Ответ:72 г.
MgCl2 + Na2CO3 = MgCo3 + 2NaCl
Mg2+ +2Cl- +2Na+ +CO3 2- = MgCO3 +2Na+ +2Cl-
<span>Mg2+ +CO3 2- = MgCO3</span>
CaC2 + H2O = C2H2 + CaO
Mr(CaC2) = 64г/моль m (CaC2)=64г
Mr(C2H2) = 26г/моль m(C2H2)=26г
128г____хг
64г____26г
х=52г
n(C2H2)= 52г/26г/моль= 2 моль
V (C2H2)= 2моль × 22,4 л/моль = 44,8 л
V (C2H2)=44,8л