a) 2Na+2H2O--->2NaOH+H2
Ta có
n H2=3,36/22,4=0,15(mol)
Theo pthh
n Na=2n H2=0,3(mol)
m Na=0,3.23=6,9(g)
b) 2NaOH+Cu(NO3)3--->Cu(OH)2+2NaNO3
Theo pthh1
n NaOH=2n H2=0,3(mol)
Theo pthh2
n Cu(OH)2=1/2n NaOH=0,15(mol)
m=m Cu(OH)2=0,15.99=14,85(g)
c) m dd sau pư=100+6,9-0,3=106,6(g)
C% NaOH=12/106,6.100%=11,26%
Chúc bạn học tốt
Na + H2O \(\rightarrow\) NaOH + 1/2H2
0,3__________0,3____0,15
nH2=\(\frac{3,36}{22,4}\)=0,15mol
mNa=0,3.23=6,9g
2NaOH + Cu(NO3)2\(\rightarrow\) Cu(OH)2 + 2NaNO3
0,3_________________0,15_______0,3
mCu(OH)2=0,15.(64+17.2)=14,7g
C%NaOH =0,3.(23+17)/100+6,9-0,15.2 .100=11,26%