Tests for organic functional groups

This question is about simple test-tube reactions to identify organic liquids.

Silver nitrate solution can be used to distinguish between propanoyl chloride and 1-chloropropane.

Give the observations you would expect when a few drops of silver nitrate solution are added to separate samples of propanoyl chloride and 1-chloropropane.

Observation with propanoyl chloride

Observation with 1-chloropropane

A student plans a series of chemical tests to confirm the identities of four organic

This is the student’s method.

To separate test tubes containing samples of each liquid:

Test 1 add potassium dichromate(VI) solution and warm gently

Test 2 add Fehling’s solution and cool in iced water

Test 3 add sodium hydrogencarbonate solution and test any gas produced with a lighted splint

Test 4 add bromine water and shake at room temperature.

Identify the missing reagent needed in Test 1.

In addition to the missing reagent in Test 1, there is a mistake in the method for two of the other tests.

State the two mistakes.

Suggest how each of the mistakes should be corrected.

The missing reagent is added and the mistakes are corrected.

Identify the liquid(s), J, K, L and M, that would react in each test.

State the expected observation for each reaction.

Liquid(s) that react in Test 1

Expected observation

Liquid(s) that react in Test 2

Expected observation

Liquid(s) that react in Test 3

Expected observation

Liquid(s) that react in Test 4

Expected observation

Figure 10 shows the apparatus that is used to separate a mixture of liquids K and M using fractional distillation.

Suggest labels that should be added to positions S, T and U in Figure 10.

Explain why fractional distillation is preferred to simple distillation to separate liquids K and M.

A student plans an experiment to investigate the yield of propanoic acid when a sample of propan-1-ol is oxidised.

Figure 4 shows the apparatus that the student plans to use for the experiment.

The student’s teacher says that the apparatus is not safe.

Give two reasons why the apparatus shown in Figure 4 is not safe.

Give one additional reagent that is needed to form any propanoic acid.

State two more mistakes in the way the apparatus is set up in Figure 4.

State the purpose of the small glass beads in the flask in Figure 4.

After correcting the mistakes, the student heats a reaction mixture containing 6.50 g of propan-1-ol with an excess of the oxidising agent. The propanoic acid separated from the reaction mixture has a mass of 3.25 g

State the name of the technique used to separate the propanoic acid from the reaction mixture.

Calculate the percentage yield of propanoic acid.

Three reagents are added separately to four organic compounds.

Which row shows the correct observations?

You are provided with samples of each of the four compounds.

Describe how you could distinguish between all four compounds using the minimum number of tests on each compound.

You should describe what would be observed in each test.