Question

chemistry

please I need report for lap experiment :

1- testing salt for cations
2- testing salt for anions
3- titration

hint:
please send copy to my email
[email protected]

Answer 1

1 and 2: Testing salt for cations and anions:

Topic - Quantitative Analysis

Time required - 1 to 2 hour

Description: To identify the cations and anions present in an unknown salt by a combination of tests.

Apparatus required: Test tube, bunsen burner, indicator paper

Chemicals required:

Ammonia solution - 2 mol dm–3

Sodium hydroxide solution - 0.4 mol dm–3 (Irritant)

Hydrochloric acid solution - 0.4 mol dm–3

Barium chloride solution - 0.1 mol dm–3 (Harmful)

Limewater solution - 0.02 mol dm–3

Nitric acid - 0.4 mol dm–3 (Irritant)

Silver nitrate solution - 0.1 mol dm–3

Unknown salt samples containing one of the following anions and one of the following cations:

Anions - OH^-, SO₄^2-, CO₃^2-, Cl^-, Br^-, I^-, NO₃^-

cations - H^+, Ca²⁺, Cu²⁺, Fe²⁺, Fe³⁺, NH₄⁺

Safety measurs:

Wear eye protection while dealing with chemicals.

Ammonia solution causes burns and gives off ammonia vapour that irritates the eyes, lungs and respiratory system.

Sodium hydroxide can cause burns and is dangerous to the eyes.

Hydrochloric acid can cause burns. Barium chloride is harmful by inhalation.

Nitric acid and silver nitrate solution cause burns.

Procedure:

1. Dissolve the unknown substance in deionised water inside a test tube. 5–10 cm³ of solution may be needed for the test.

2. Test a small aliquots by using the analysis table.

3. The following tests need to be carried out to conform the presence of a particular cation and anion.

(a) Test for anions: Carry out the following 3 tests A, B and C for anions

(b) Test for cations: Carry out the following 3 tests D and E for cations

4.. Repeat the test for the other unknown samples.

Things to be record:

5. Flame test:

(a). Slightly open the air hole of the Bunsen burner.

(b).Heat a piece of nichrome wire in a Bunsen flame until the flame is no longer

Coloured.

(c).Dip the loop at the end of the wire into some water.

(d).Dip the loop into the unknown salt.

(e).Hold the wire at the edge of the flame.

(f). Record the colour and identify the cation using the table below.