\(n_{Al_2S_3}=\dfrac{25.5}{150}=0.17\left(mol\right)\)
\(n_{Al}=\dfrac{10.8}{27}=0.4\left(mol\right)\)
\(2Al+3S\underrightarrow{^{t^0}}Al_2S_3\)
\(0.34...........0.17\)
\(H\%=\dfrac{0.34}{0.4}\cdot100\%=85\%\)
n Al2S3 = 25,5/150=0,17(mol)
$2Al + 3S \xrightarrow{t^o} Al_2S_3$
n Al = 2n Al2S3 = 0,34(mol)
H = 0,34.27/10,8 .100% = 85%