Waec Recommendation for chemistry practicals 2020/2021

(a) GENERAL SKILLS AND PRINCIPLES

 Candidates will be expected to be familiar with the following skills and principles:

(i) Measurement of mass and volume;

(ii) Preparation and dilution of standard solutions;

(iii) Filtration, recrystallisation and melting point determination;

(iv) Measurement of heats of neutralization and solutions;

(v) Determination of pH value of various solutions by colorimetry;

(vi) Determination of rates of reaction from concentration versus time curves;

 (vii) Determination of equilibrium constants for simple system.

(b) QUANTITATIVE ANALYSIS

Acid-base titrations

The use of standard solutions of acids and alkalis and the indicators; methyl orange, 

methyl red and phenolphthalein to determine the following:

(i) The concentrations of acid and alkaline solutions;

(ii) The molar masses of acids and bases and water of crystallization.

(iii) The solubility of acids and bases;

(iv) The percentage purity of acids and bases;

(v) Analysis of Na2CO3/NaHCO3 mixture by double 

indicator methods (Ghanaians only).

(vi) Stoichiometry of reactions.

Redox titrations

Titrations of the following systems to solve analytical problems:

(i) Acidic MnO4

– with Fe2+;

(ii) Acidic MnO4

– with C2O4

2-

;

(iii) I2 in KI versus S2O3

2-

.

(d) QUALITATIVE ANALYSIS

 No formal scheme of analysis is required.

(i) Characteristic tests of the following cations with dilute NaOH(aq) and NH3(aq);

 NH4; Ca2+; Pb2+; Cu2+; Fe2+; Fe3+; Al3+; and Zn2+

.

(ii) Confirmatory tests for the above cations.

(iii) Characteristic reaction of dilute HCl on solids or aqueous solutions and conc. 

H2SO4 on solid samples of the following:

Cl-

; SO3

2-

; CO3

2-

; NO3

and SO4

2-

.

(iv) Confirmatory tests for the above anions

(v) Comparative study of the halogens; displacement reactions.

(vi) Characteristic tests for the following gases: H2; NH3; CO2; HCl and SO2.

(vii) Characteristic test tube reactions of the functional groups in the following simple 

organic compounds: Alkenes; alkanols; alkanoic acids, sugars (using Fehiling’s 

and Benedict’s solutions only); starch (iodine test only) and proteins (using the 

Ninhydrin test, Xanthoporteic test, Biuret test and Millon’s test only).

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