Bài 2:
a)
\(n_{MgCl_2}=0,15.1=0,15\left(mol\right)\)
PTHH: MgCl2 + 2NaOH --> Mg(OH)2\(\downarrow\) + 2NaCl
0,15---->0,3--------->0,15
\(\Rightarrow m_{Mg\left(OH\right)_2}=0,15.58=8,7\left(g\right)\)
b) \(C_{M\left(dd.NaOH\right)}=\dfrac{0,3}{0,2}=1,5M\)
c)
PTHH: Mg(OH)2 --to--> MgO + H2O
0,15---------->0,15
=> m = 0,15.40 = 6 (g)