a, Ta có:
\(n_{Mg}=0,03\left(mol\right)\)
\(PTHH:2Mg+O_2\rightarrow2MgO\)
\(\Rightarrow n_{MgO}=n_{Mg}=0,03\left(mol\right)\)
\(\Rightarrow m_{MgO}=1,2\left(g\right)\)
b,\(2KClO_3\rightarrow2KCl+3O_2\)
\(n_{O2}=0,015\left(mol\right)\Rightarrow n_{KClO3}=0,01\left(mol\right)\)
\(\Rightarrow m_{KClO3}=1,225\left(g\right)\)