Ta có: \(n_{Al}=\dfrac{12,15}{27}=0,45\left(mol\right)\)
\(n_{CuSO_4}=\dfrac{54}{160}=0,3375\left(mol\right)\)
PT: \(2Al+3CuSO_4\rightarrow Al_2\left(SO_4\right)_3+3Cu\)
Xét tỉ lệ: \(\dfrac{0,45}{2}>\dfrac{0,3375}{3}\), ta được Al dư.
Theo PT: \(n_{Al\left(pư\right)}=\dfrac{2}{3}n_{CuSO_4}=0,225\left(mol\right)\)
\(\Rightarrow n_{Al\left(dư\right)}=0,225\left(mol\right)\Rightarrow m_{Al\left(dư\right)}=0,225.27=6,075\left(g\right)\)
Theo PT: \(n_{Al_2\left(SO_4\right)_3}=\dfrac{1}{3}n_{CuSO_4}=0,1125\left(mol\right)\)
\(\Rightarrow m_{Al_2\left(SO_4\right)_3}=0,1125.342=38,475\left(g\right)\)