\(n_{Na}=\dfrac{m}{M}=\dfrac{3,45}{23}=0,15\left(mol\right)\\ n_{Na_2O}=\dfrac{m}{M}=\dfrac{6,2}{62}=0,1\left(mol\right)\\ PTHH:2Na+2H_2O->2NaOH+H_2\left(1\right)\)
tỉ lệ 2 : 2 : 2 ; 1
n(mol) 0,15---->0,15------->0,15----->0,075
\(m_{NaOH\left(1\right)}=n\cdot M=0,15\cdot40=6\left(g\right)\)
\(PTHH:Na_2O+H_2O->2NaOH\left(2\right)\)
tỉ lệ 1 ; 1 ; 2
n(mol) 0,1----->0,1------->0,2
\(m_{NaOH\left(2\right)}=n\cdot M=0,2\cdot40=8\left(g\right)\\ =>m_{NaOH}=m_{NaOH\left(1\right)}+m_{NaOH\left(2\right)}=6+8=14\left(g\right)\)