Question

rated C-H Single bonds O-HV b) Name the two major chemical tests you would perform on the infrared spectrum pictured above. Test 1_ Jones Test (.5 pt) Test 2_ Lucas Test (.5 pt) 2. What test (name of the test and reagents included) could be used to distinguish between each pair of compounds? Explain the expected observations for each compound (2 pts each): 1) 1-butanol and 2-butanol 2) butanal and 2-butanone 3) propanal and ethyl acetate 4) ethyl acetate and methyl ethyl ketone

Answer 1

2.

1)

1-butanol and 2-butanol

1-butanol is primary alcohol and 2-butanol is secondary alcohol

We need to distinguish primary alcohol from secondary alcohol.

Lucas test (anhydrous zinc chloride and conc HCl)

On reaction, 1-butanol will have no effect. 2-butanol solution turns cloudy after 3-5 minutes.

2)

Butanal and 2-butanone

Butanal is an aldehdye and 2-butanone is a ketone

We need to distinguish an aldehyde from a ketone

Tollens reagent (ammoniacal silver nitrate solution) forms a silver mirror with butanal. This test is not given by 2-butanone.

3)

Propanal and ethyl acetate

Propanal is an aldehyde and ethyl acetate is an ester

Tollens reagent (ammoniacal silver nitrate solution) forms a silver mirror with propanal. This test is not given by ethyl acetate.

4)

Ethyl acetate is an ester and methyl ethyl ketone is a methyl ketone.

We need to distinguish an ester from a methyl ketone

Iodoform test (Iodine and NaOH) is given by methyl ketones. It is not given by esters.

Methyl ethyl ketone forms pale yellow precipitate of iodoform when treated with iodine and NaOH. However no precipitate is formed with ethyl acetate.