Question

Please help with 3 b and 4 a , b , c and e! Irrelevant answers will be reported!* ASAP!T_T

Answer 1

3.Test for unsaturation is carried out by either Baeyer's test or bromine water test.

(a) What is Baeyer's reagent?

Ans:

Baeyer's reagent is an alkaline solution of Potassium Permanganate
`\bold{KMnO_4}` .

(b) How does it detect presence of double bond in organic compound? Write the reaction involved.

Ans:

When a dilute alkaline solution of
`\bold{KMnO_4}` is added to the given unsaturated organic compound, if the purple color of permanganate solution disappears, the presence of double bond is indicated.

For example:

2
`\bold{KMnO_4}` + 2KOH
`\longrightarrow`
`\bold{2K_2MnO_4 + H_2O+[O]}`

`\bold{CH_2=CH_2(ethene) +H_2O+[O]\longrightarrow CH_2OH-CH_2OH (ethylene \:glycol :Colourless)}`

(c) Write the product when ethyne is treated with Baeyer's reagent.

Ans:

Product will not produce as ethyne doesn't contain double bond.

(d) Benzene (an aromatic hydrocarbon) does not give Baeyer's test though it has double bonds. Why?

Ans:

As Benzene is an unsaturated compound. The structure of benzene contains 3 alternate single double bonds.

(e) Write the reaction for bromine water test for ethyne.

Ans:

Reaction:

`\bold{CH_2CH_2(ethene)+Br_2( red \: color) \longrightarrow CH_2Br-CH_2Br}`

(1,2-dibromoethane (colorless}

Kolbe electrolytic method can be used to prepare alkane, alkene and alkyne.

(a) At which electrode, alkane, alkene or alkyne is obtained?

Ans:

alkane, alkene or alkyne is obtained at anode.

(b) Which electrolyte should be chosen for alkane, alkene or alkyne for the method? Suggest an example of electrolyte for each.

Ans:

alkane: Potassium or sodium salt of Carboxylic acid

alkene: Potassium or sodium salt of dicarboxylic acid

alkyne: Potassium or sodium maleate

(c) If potassium salt of dicarboxylic acid is taken for the method, which hydrocarbon is prepared?

Ans: If potassium salt of dicarboxylic acid is taken for the method, Alkene hydrocarbon is prepared.

(d) Write the detail process for the electrolysis of aqueous potassium maleate.

Ans: Attachment

(e) Suggest a demerit of the method.

Ans:

Demerits:

• Kolbe electrolysis can produce a mixture of different products, including both desired and undesired ones.
• It requires a significant amount of energy to produce the desired products. This can make the process expensive and inefficient.
• It is limited to the electrolysis of alkanes with low molecular weight, and it may not be suitable for the electrolysis of more complex organic molecules.
• This process generates significant amounts of waste and can produce pollutants that can harm the environment.