C + 2H2 = CH4
CH4 + Br2 = CH3Br + HBr
2CH3Br + 2Na = CH3-CH3 + 2NaBr
CH3-CH3 + Cl2 = CH3-CH2Cl + HCl
2CH3-CH2Cl + 2Na = CH3-CH2-CH2-CH3 + 2NaCl
CH3-CH2-CH2-CH3 =(t)= CH3-CH3 + CH2=CH2
2CH3-CH3 + 7O2 = 4CO2 + 6H2O
Формула во вкладке.......
2Mg+O2= 2MgO
M(Mg)=24г/моль
"ню"(Mg)="ню"(MgO)= 0,5 моль
0,5*40(M(MgO))=20г
Ответ: 20г
<span> Al2o3 Al2(+3) o3(-2)</span>
<span><span>Li2Se Li2(+1) Se(-2)</span></span>
<span><span><span>Mgbr2 Mg(+2) Br2(-1)</span></span></span>
<span><span><span><span>SF6 S(+6) F6(-1)</span></span></span></span>
<span><span><span><span><span>HRO3 H(+1) R(+5) O3(-2)</span></span></span></span></span>
<span><span><span><span><span><span>H2CO3 H2(+1) C(+4) O3(-2)</span></span></span></span></span></span>
<span><span><span><span><span><span><span>KNO3 K(+1) N(+5) O3(-2)</span></span></span></span></span></span></span>
Закрыть окно(чтобы не летела с улицы вода и т.д.),подмести пол,убрать с пола мусор