Multiple choice Which of the following is the I.U.P.A.C name of CH3CH2CH=CH2? Butane Prop-1-ene But-2-ene Butyne But-1-ene Reveal answer Fill a bubble to check yourself E Correct answer Explanation Counting the number of carbon atoms i.e. 4 and it has one double bond at first position of carbon. CH3CH2CH=CH2. Buta + ene = but-1-ene