Answer:
The percent yield is 70.486%
Explanation:
[tex]3CuSO_{4}+2Al\longrightarrow Al_{2}(SO_{4})_{3}+3Cu\\\\Weight\:of\:Al=1.87g\\54g\:of\:Al\:will\:give\:190.5g\:of\:Cu\\[/tex]
[tex]1.87g\:of\:Al\:gives=\frac{190.5\times1.87}{54}=6.597g\:of\:Cu\\ \\Weight\:of\:Cu\:obtained=4.65g\\Theoretical\:Yield=6.597g\\Experimental\:Yield=4.65g\\Percent\:Yield=\frac{Experimental\:Yield}{Theoretical\:Yield}\times100=\frac{4.65}{6.597}\times100=70.486\%[/tex]
Hence, the percent yield is 70.486%