Question

Answer 1

Câu 5 : 

$2NaOH + CO_2 \to Na_2CO_3 + H_2O$

$n_{CO_2} = n_{Na_2CO_3} = \dfrac{15,9}{106} = 0,15(mol)$
$m_{hh\ muối} = m_{oxit} + m_{CO_2} = 7,6 + 0,15.44 = 14,2(gam)$

Answer 2

Câu 6 : 

\(n_{H_2}=\dfrac{5.6}{22.4}=0.25\left(mol\right)\)

\(2M+2nHCl\rightarrow2MCl_n+nH_2\)

\(\dfrac{0.5}{n}.........................0.25\)

\(M_M=\dfrac{16.25}{\dfrac{0.5}{n}}=\dfrac{65}{2}n\)

\(n=2\Rightarrow M=65\)

\(M:Zn\)

\(V_{dd_{HCl}}=\dfrac{0.25\cdot2}{0.2}=2.5\left(M\right)\)