ERIMENT 1: DETERMINATION OF ANIONS IN SOLUTION
statue Analysts
EORY: Anions are detected under two conditions: - (i) By heating the salt with dilute hydrochloric acid and
dentifying the gas evolved based on its properties.
(ii) By reacting the salt with concentrated tetraoxosulphate (vi) acid. The anion is also identified based on the
properties of the evolved gas. This acid is dangerous and MUST be handled with care.
PROCEDURE:
You are provided with four different compounds labeled w, x, y and z. In each case, carry out the following tests,
record your observations and inference in a table.
(a) Use a spatula to transfer a small portion of compound w into a clean test tube and add dilute hydrochloric acid
to it. Note the gas evolved. Test the gas liberated with moist red and blue litmus papers
separately. Bubble the
gas through lime water.
(b) Use compound x and follow the same procedure as in (a) above. Bubble the gas produced through the
following:
(i) Acidified potassium tetraoxomanganate (VII) solution.
(ii) Acidified potassium heptaoxodichromate (VI) solution.
(iii) Lead (II) ethanoate solution
Use compound y and follow the same procedure as in (a) above. This time you need to heat. Bubble the gas
liberated through the following:
(i) Acidified KMnO4 (aq)
(ii) Acidified K2Cr2O7
(iii) (CH3COO)2Pb (aq)
(d) Add water sample Z in a beaker. Transfer 2.00 cm³ of the resulting solution of sample Z into a test tube. Add
barium chloride solution, note if there is any colour change and finally add dilute HCI. Note your observation
and draw your inference.
Questions
1. Write equation of the reaction in (a)
2. Write separate equation of the reactions in (b) (i) and (b) (ii)
3. Write separate equation of the reactions in (c) (i), (c) (ii), and (c) (iii).
4. Write equation of the reaction (d) above.


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