Compare acetyleneand benzene with respect to the following: (a) hybridisationof carbon atoms, (b) percentage compositions of C and H, (c ) product of ozonolysisand (d) reaction with Baeyer's reagent.

Compare acetyleneand benzene with respect to the following: (a) hybri

1.	Compare acetyleneand benzene with respect to the following: (a) hybridisationof carbon atoms, (b) percentage compositions of C and H, (c ) product of ozonolysisand (d) reaction with Baeyer's reagent.
Answer» Solution :(a) In acetylene, both carbon atoms are sp hybridised, while in benzene all carbon atoms are `sp^2` hybridised.(b) The percentage composition of carbon as well as hydrogen in both acetylene and benzene is SARE, since the empirical formula is same. Percent carbon in benzene = `(72 xx 100)(78) = 92.4` Percent carbon in acetylene = `(24 xx 100)/(26) 92.4` Percent hydrogen in benzene = `(6 xx 100)/(78) = 7.6` Percent hydrogen in acetylene = `(2 xx 100)/(26) = 7.6` (c)Both acetylene and benzene on ozonolysis give glyoxal. One mole of acetylene on ozonolysis gives one mole of glyoxal, but one mole of benzene gives three moles of glyoxal. (d) Acetylene decolourises pink colour of Baeyer.s reagent, but benzene does not. Acetylene is oxidised by Baeyer.s reagent to give oxalic acid `C_2H_2 + 4(O) overset(MnO_4^(-), OH^(-))(rarr)HOOC-COOH ` Benzene is not oxidised by Baeyer.s reagent.