Which one is the correct order of acidity? (NEET 2017)

Alkanes, alkenes and alkynes follow the following trend in their acidic behaviour : 2 2 3 3 2 2 3 3 HC CH H C C H C H C H sp sp sp sp sp sp This is because sp-hybridised carbon is more electronegative than sp2-hybridised carbon which is further more electronegative than sp3-hybridised carbon. Hence, in ethyne proton can be released more easily than ethene and ethane. Among alkynes the order of acidity is: CH≡CH > CH3–C≡CH > CH3–C≡C—CH3 This is due to +I effect of —CH3 group. HYDROCARBONS 38