Chemistry Paper 3A WASSCE (SC), 2017

Question 2B

E is a mixture of an organic compound and an inorganic salt.
Carry out the following exercises on E. State the conclusions you draw from the result of each test.

  1. Put all of E in a boiling tube or beaker and add about 10cm3 of distilled water. Stir the mixture well and filter. Keep both the filtrate and residue.
  2. To about 5 cm3 of the filtrate, add about 2 cm3 of fehling’s solution and warm.
  3. (i) To the residue, gently add about 5 cm3 dilute HCl. Divide the solution into two portions.
    (ii) To the first portion, add NaOH(aq) in drops and then in excess.
    (iii) To the second portion of the solution, add NH3(aq) in drops and then in excess. [ 19 marks]

Observation

 

TThis question tested the skills of candidates in qualitative analysis. Candidates were asked to carry out qualitative analysis on salt E that contained a mixture of organic and inorganic salts.
In part (a), majority of the candidates could differentiate between filtrate and residue.
In part (b), majority of the candidates wrote correct observations and inferences
In part (c), majority of the candidates correctly used the term “gelatinous” when writing their inferences.The expected answers include

Expected answers include:-