The major product formed after the elimination of HBr from but-1-ene in the presence of a strong base is but-1-yne. The balanced chemical equation for the reaction is:C4H8 + 2 KOH C4H6 + 2 H2O + 2 KBrBut-1-ene C4H8 reacts with two equivalents of a strong base, such as potassium hydroxide KOH , to form but-1-yne C4H6 , water H2O , and potassium bromide KBr .