Complete the equation: CH 3 - CHBr - CH 2 Br → Alc . KOH

When vicinal or 1 , 2 - dihalo compounds are treated with alcoholic potassium hydroxide, two molecules of hydrogen halides are eliminated from adjacent carbon atoms to give alkynes. CH 3 - CHBr - CH 2 Br → - HBr alc . KOH CH 3 - C Br = CH 2 → - HBr alc . KOH CH 3 - C ≡ CH

Complete the equation: R - C ≡ CH → ammoniacal AgNO 3

Alkyenes react with ammoniacal solution of silver nitrate (Tollen's reagent) to form a white precipitate. R - C ≡ CH + Ag NH 3 2 + OH - → R - C ≡ CAg + H 2 O + 2 NH 3 This reaction is a test to determine terminal alkyne group. This test does not hold true for internal multiple bond.

Complete the equation: HC ≡ CH + 2 Na → liq . NH 3

Acetylene and terminal alkynes react with sodamide i.e sodium in liquid ammonia, at 475 K to form disodium acetylide. This is an example of substitution reaction. HC ≡ CH + 2 Na → liq . NH 3 NaC ≡ CNa + NH 3

Complete the equation: R - C ≡ CH + HOCl →

Alkynes add two molecules of hypohalous acid in two steps forming a dihaloaldehyde in case of acetylene or dihaloketone in case of alkyl acetylene. The addition takes place according to Markownikoff's rule.

Complete the equation: CH 3 - C ≡ CH → HgSO 4 42 % H 2 SO 4

When propyne is passed over 42 % H 2 SO 4 at 60 ° C in the presence of HgSO 4 , an unstable compound vinyl alcohol is formed which further rearranges to form propanone. The addition takes place according to Markownikoff's rule. CH 3 - C ≡ CH → HgSO 4 42 % H 2 SO 4 [ CH 3 - C OH = CH 2 ] ⇌ CH 3 - C O - CH 3

Identify the compound A and B . A → O 3 B → water CH 3 COOH + CH 3 COOH

This is a type of oxidation reaction. When alkynes react with ozone, the rate of formation of ozonide is slower than that in alkenes. The ozonide on decomposition with zinc in water undergo lysis to form corresponding carboxylic acids. When 2 - butyne undergoes ozonolysis, two molecules of acetic acid is formed.

Identify the compound A and B . A → electrolysis B → 2 Br 2 Br 2 CH - CHBr 2

When concentrated solution of sodium or potassium salt of maleic acid or fumaric acid is electrolysed, acetylene is obtained at the anode. This reaction is known as Kolbe's electrolytic method. When bromine is added to acetylene in dark at room temperature in the absence of solvent, addition reaction takes place to form, 1 , 1 , 2 , 2 - tetrabromoethane. Salt of Fumaric acid / Maleic acid → electrolysis HC ≡ CH → 2 Br 2 Br 2 HC - CHBr 2 Kolbe's electrolytic method is given as: