2Al+3Br2->2AlBr3
0,3---0,45----0,3 mol
n Al=\(\dfrac{8,1}{27}\)=0,3 mol
=>mBr2=0,45.160=72g
=>m AlBr3=0,3.267=80,1g
\(n_{Al}=\dfrac{8,1}{27}=0,3\left(mol\right)\\ 2Al+3Br_2\rightarrow2AlBr_3\\ n_{AlBr_3}=n_{Al}=0,3\left(mol\right)\\ n_{Br_2}=\dfrac{3}{2}.0,3=0,45\left(mol\right)\\ m_{AlBr_3}=267.0,3=80,1\left(g\right)\\ m_{Br_2}=0,45.160=72\left(g\right)\)