Question

Tìm R

a

\(R+HCl\rightarrow RCl_2+H_2\)

biết \(m_R=13\left(g\right);m_{RCl_2}=27,2\left(g\right)\)

b

\(R+HCl\rightarrow RCl_n+H_2\)

biết \(m_R=3,78\left(g\right);V_{H_2}=4,704\left(l\right)\)

Answer 1

\(a,PTHH:R+2HCl\rightarrow RCl_2+H_2\)

Theo phương trình trên:
\(n_R=n_{RCl_2}\)

\(\Leftrightarrow\frac{13}{R}=\frac{27,2}{R+71}\)

\(\Leftrightarrow27,2R=13\left(R+71\right)\)

\(\Leftrightarrow R=65\).

Vậy \(R\) là \(Zn\)

\(b,2R+2n_{HCl}\rightarrow2RCln+n_{H_2}\)

\(n_{H_2}=\frac{4,704}{22,4}=0,21\left(mol\right)\)
\(\Rightarrow n_R=\frac{0,42}{n}mol\)
\(M_R=\frac{3,78n}{0,42}=9n\)

\(n=3\Rightarrow M_R=27\)

Vậy \(R\) là \(Al\)