Core Practical 7 Lab

Aim

To identify several unknown colourless liquids and inorganic solids

Equipment

● dropping bottle of A ● dropping bottle of B ● dropping bottle of C ● solid X ● solid Y ● solid Z ● bromine water ● spatula ● distilled water ● Fehling’s solution ● barium chloride solution ● acidified potassium dichromate ● apparatus to conduct a flame test ● silver nitrate solution ● ethanol ● chlorine water ● dilute ammonia solution ● test tubes ● 250 ml beaker ● nitric acid ● dilute sodium hydroxide ● kettle

Part 1 Perform the following tests on each of the organic liquids, A, B, and C:

1. Place 10 drops of each liquid into three separate test tubes. Add a 1 cm depth of bromine water to each test tube and shake the mixture.

2. Place 10 drops of each liquid into three separate test tubes. Add 1 cm3 acidified potassium dichromate to each test tube and warm the mixture in a 60 °C water bath for 5 minutes.

3. Place 10 drops of each liquid into three separate test tubes. Add 1 cm3 of Fehling’s solution to each test tube and heat the resultant in the water bath.

4. Place 10 drops of each liquid into three separate test tubes. Add 1 cm3 of ethanol and 1 cm3 of dilute sodium hydroxide solution to each test tube and warm the mixture in a water bath for five minutes. Acidify each mixture with dilute nitric acid and then add 5 drops of silver nitrate solution.

Part 2 Perform the following tests on each of the inorganic solids, X, Y, and Z:

1. Conduct flame tests for each of the three solids.

2. Dissolve a spatula full of each solid in three separate test tubes containing 10 cm3 distilled water. Split each solution into three portions.

(a) To the first portion, add 5 cm3 dilute nitric acid followed by 10 drops of silver nitrate solution. Add dilute ammonia solution.

(b) To the second portion, add 5 cm3 dilute nitric acid followed by 10 drops of barium chloride solution.

(c) To the third portion, add 2 cm3 of chlorine water.