a) \(n_{Na}=\dfrac{2,3}{23}=0,1\left(mol\right)\)
PTHH: \(2Na+2H_2O\rightarrow2NaOH+H_2\)
0,1------------------->0,1-->0,05
\(m_{H_2O}=47,8.1=47,8\left(g\right)\)
\(C\%_{NaOH}=\dfrac{0,1.40}{2,3+47,8-0,05.2}.100\%=8\%\)
\(C_M=\dfrac{0,1}{0,0478}=2,092M\)
b) 50 (g) dd NaOH có thể tích 0,0478 (l)
=> 100 (g) dd NaOH có thể tích 0,0956 (l)
\(n_{NaOH}=\dfrac{100.8\%}{40}=0,2\left(mol\right)\)
\(n_{CuCl_2}=1,532.0,0522=0,08\left(mol\right)\)
PTHH: \(2NaOH+CuCl_2\rightarrow Cu\left(OH\right)_2+2NaCl\)
Xét tỉ lệ: \(\dfrac{0,2}{2}>\dfrac{0,08}{1}\) => NaOH dư, CuCl2 hết
PTHH: \(2NaOH+CuCl_2\rightarrow Cu\left(OH\right)_2+2NaCl\)
0,16<----0,08--------->0,08----->0,16
\(\left\{{}\begin{matrix}C_{M\left(NaCl\right)}=\dfrac{0,16}{0,0956+0,0522}=1,08M\\C_{M.NaOH}=\dfrac{0,2-0,16}{0,0956+0,0522}=0,27M\end{matrix}\right.\)