Odpowiedź :
but-1-en CH=CH-CH2-CH3
CH2=CH-CH2-CH3 + H2 -----> CH3-CH2-CH2-CH3 (butan)
CH2=CH-CH2-CH3 + Br2 -----> CH2Br-CHBr-CH2-CH3 (1,2-dibromobutan)
but-2-en CH3-CH=CH-CH3
CH3-CH=CH-CH3 + H2 -----> CH3-CH2-CH2-CH3 (butan)
CH3-CH=CH-CH3 + Br2 -----> CH3-CHBr-CHBr-CH3 (2,3-dibromobutan)