KCSE Chemistry Paper 1 Sample 2022
KCSE Chemistry Paper 1 tests your ability to apply atomic structure, bonding theory, and quantitative reasoning to novel problems—skills that separate top scorers from the rest. This sample paper drills atoms and molecular structure, quantitative chemistry and the mole concept, and energy changes and oxidation-reduction, using the same question styles and mark weights you'll encounter in the real exam. Designed for Form 4 students revising the full KCSE Chemistry syllabus, it gives you realistic practice in 90 minutes. After working through it, you'll confidently predict the examiner's next move in any structural or stoichiometric question, and spot the common traps before they cost you marks.
Questions in this quiz
Answers hidden — play to find out.
- Question 1
An element X has an electronic configuration of 2, 8, 7. Which of the following correctly identifies element X and predicts its bonding behaviour?
- Question 2
Which of the following pairs of elements is most likely to form an ionic compound?
- Question 3
Copper exists as two stable isotopes: ⁶³Cu (69%) and ⁶⁵Cu (31%). What is the relative atomic mass of copper?
- Question 4
True or False: An atom is electrically neutral because the number of protons equals the number of electrons.
- Question 5
Calculate the molar mass of calcium carbonate (CaCO₃). (Relative atomic masses: Ca = 40, C = 12, O = 16)
- Question 6
How many moles of oxygen atoms are present in 0.5 mol of sodium nitrate (NaNO₃)?
- Question 7
In the reaction: 2H₂ + O₂ → 2H₂O, if 4 mol of hydrogen gas reacts completely, how many moles of water are produced?
- Question 8
A compound contains 40% carbon and 60% oxygen by mass. If its molar mass is 60 g/mol, what is its molecular formula? (Atomic masses: C = 12, O = 16)
- Question 9
Which of the following is an exothermic reaction?
- Question 10
True or False: In a redox reaction, the oxidation state of an element always changes.
- Question 11
In the reaction: Zn + CuSO₄ → ZnSO₄ + Cu, which element is oxidised?
- Question 12
Balance the following redox equation in acidic solution: MnO₄⁻ + Fe²⁺ → Mn²⁺ + Fe³⁺
- Question 13
A student burns 2.4 g of magnesium in oxygen. If the molar mass of magnesium is 24 g/mol, how many moles of magnesium reacted?
- Question 14
Which of the following elements would have the smallest atomic radius?