Biology examination questions.
ZIMSEC Prac exam questions. There are usually three questions on Paper 4. The examiners will take care to
Scientific drawings biology practical
Scientific drawings. They are an important part of the of biology practical and all candidates must able to
Reaction of Manganese Mn2+
Reaction of Manganese, Mn2+ Color : pale pink, almost colourless Test Observations Notes Add NaOH(aq) An off-white ppt
Reaction of Cr3+
Reaction of Cr3+ Its colour is green. A solution of Cr3+ is commonly provided in form of CrCl3(aq).
reaction-of-iron-fe2-and-fe3
Reaction of iron(ii), Fe2+ Colour : pale green, almost colourless. Test Observation Notes Add H2O2 Then add
Reaction of Copper
Reaction of Copper, Cu2+ Cu2+(aq) (pale blue) 1ons can be obtained b Dissolving a solub1e copper (II) salt
Qualitative Analysis Invariably involves detection or identification of cation(s) and or anion(s) present in given test substance in
Reducing Agents
Reducing Agents Commonly used reducing agents include; KI-iodides; Sodium thiosulphate -thiosulphate ions Potassium Iodide, KI I–(aq) is oxidized
Oxidizing Agents
Oxidizing Agents Common used oxidizing agents include; KMnO4 K2CrO7 H2O2 *usually requires acidic conditions eg adding sulphuric acid