BaCl2 + Na2CO3 -> BaCO3↓ + 2NaCl
1)2 Mg + O2 = 2MgO
Mg + Cl2 = MgCl2
Mg + S = MgS
3Mg + N2 = Mg3N2
Mg + H2 = MgH2
Mg + C = Mg2C
2) Дано: Решение:
Mr(Al2(SO4)3) = 342 г/моль W(Al) = Ar(Al) *n / Mr(Al2(SO4)3) *100% =
Найти: = 27 * 2 / 342 *100% = 15,79%
W(Al) =?
1) NaCl---> Na(+)+Cl(-)
2)<span>KNO3---></span><span>K(+)+NO3(-)</span>
<span>3)<span>CaCO3---></span><span>не диссоц</span></span>
<span><span>4)<span>Na3PO4--->3</span><span>Na(+)+PO4(3-)</span></span></span>
<span><span><span>5)<span>Cu(NO3)2---><span>Cu(2+)+2NO3(-)</span></span></span></span></span>
<span><span><span><span><span>6)<span>BaSO4--- не диссоц</span></span></span></span></span></span>
<span><span><span><span><span><span>7)<span>Fe(NO3)2---><span>Fe(2+)+ 2NO3(-)</span></span></span></span></span></span></span></span>
<span><span><span><span><span><span><span><span>8)<span>Fe2(SO4)3--->2</span><span>Fe(3+)+3SO4(2-)</span></span></span></span></span></span></span></span></span>
<span><span><span><span><span><span><span><span><span>9)<span>Ca3(PO4)2--- не диссоц</span></span></span></span></span></span></span></span></span></span>
<span><span><span><span><span><span><span><span><span><span>10) <span>K2SiO3--->2</span><span>K(+)+ SiO3(2-)</span></span></span></span></span></span></span></span></span></span></span>
1)CH4
М(CH4)=12+4*1=16г/моль
w(C)=12:16*100%=75%
2)C2H5
M(C2H5)=12*2+5*1=29г/моль
w(C)=24:29*100%=83%
75%<83%
Ответ:В этане массовая доля углерода больше.