\(Zn+X_2\rightarrow ZnX_2\)
\(n_{Zn}=\dfrac{1,3}{65}=0,02\left(mol\right)\)
\(n_{ZnX_2}=n_{Zn}=0,02\left(mol\right)\)
\(\Rightarrow M_{ZnX_2}=\dfrac{4,5}{0,02}=225\left(g/mol\right)\)
\(\Leftrightarrow2X+65=225\)
\(\Leftrightarrow X=80\left(Br\right)\)
\(n_{Br_2}=n_{Zn}=0,02\left(mol\right)\Rightarrow V_{Br_2}=0,02.22,4=0,448\left(l\right)\)