2Al+3H2S=Al2S3+3H2 m(Al)=2.7 г n(Al)=m/M=2.7/27=0.1 моль n(Al)/2=n(Al2S3)/1 => n(Al2S3)=0.05 моль m(Al2S3)=n*M= 0.05*150=7.5 г