Mg+NaOH=не идёт
2Al+6NaOH+6H2O=2Na3[Al(OH)6]+3H2
n(H2)=3.36/22.4=0.15моль
n(Al)=0.15*2/3=0.1моль
m(Al)=0.1*27=2.7г
w(Al)=2.7/10*100=27%
Mg+NaOH=не идёт
2Al+6NaOH+6H2O=2Na3[Al(OH)6]+3H2
n(H2)=3.36/22.4=0.15моль
n(Al)=0.15*2/3=0.1моль
m(Al)=0.1*27=2.7г
w(Al)=2.7/10*100=27%