CH2=CH2+HBr=CH3-CH2-Br
CH3-CH2-Br+H2O=CH3-CH2-OH+HBr
CH3-CH2-OH+CuO=Cu+CH3COH+H2O
CH3COH+Ag2O=2Ag+CH3COOH
CH3COOH+CH3OH=CH3COOCH3+H2O
C6H5OH+Br2--->C6H5BrO +HBr
m(C6H5OH)=235g/94g/mol=2,5mol
m(C6H5BrO)=2,5mol*173g/mol=432,5g
w(C6H5BrO)=100%-20%=80%=0,8
m(C6H5BrO)чистый=432,5g*0,8=346g