\(n_{AgNO_3}=2.0,3=0,6\left(mol\right)\Rightarrow m_{AgNO_3}=0,6.108=64,8\left(g\right)\)
\(m_{H_2O}=0,05.18=0,9\left(g\right)\)
\(n_{MgCl_2}=0,5.0,2=0,1\left(mol\right)\Rightarrow m_{MgCl_2}=0,1.95=9,5\left(g\right)\)
\(n_{H_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\Rightarrow m_{H_2}=0,3.2=0,6\left(g\right)\)