Question

give two methods of preparetion of acetylene.how does it react with water and hydrogen bromide??​

Answer 1

Answer:

Explanation:

give two methods of preparetion of acetylene.how does it react with water and hydrogen bromide??​

Methods of prepartion of Acetylen:

1. Dehydrohalogenation: Dibromoethane on heating with alcoholic KOH undergoes dehydrohalogenation and gives acetylene.

From iodoform: Iodoform on heating with silver powder gives acetylene.

CH3+6Ag+CHI3Iodoform→HC≡CH+6AgIAcetylene

Properties of Acetylene:

1. Action with water: When acetylene gas is passed through di. H2SO4 below 60∘ in presence of HgSO4. it undergoes addition with water forming acetaldehyde.

HC≡CH+H.OHAcetylene Water−→−−−−1%H2SO430%H2SO4[CH2=CH.OH]Vinyl alcohol→CH3.CHOAcetaldehyde

2. Action with ozone: Acetylene reacts with ozone and undergoes addition to form acetylene ozonide. This on hydrolysis in presence of Zn gives gloxal.

Answer 2

Two methods for preparing Acetylene are Calcium carbide and Vicinal dihalides.

Explanation:

• Acetylene is the common name for the unsaturated organic compound with triple bonds in it, which is 'Ethyne' and has the formula.

• Methods of preparation:

1) By calcium carbide: It is the easiest method, in which calcium carbide is mixed with water as the reactants and the products we get are Calcium hydroxide and Ethyne or acetylene.

2) By Vicinal dihalides: Vicinal dihalides are organic compounds that consist of two halogens. When the vicinal dihalides are reacted with Alcoholic potassium hydroxide, an alkenyl halide is obtained, and by further reacting it with soda-lime, it gives us an alkyne.

• The reaction of acetylene with water gives us an unstable compound, which rearranges itself to form acetaldehyde.
• When acetylene is reacted with HBr, then it forms Ethylidene bromide.