Summary

• Description:

  The PDF document comprises KALA Joint Trials Chemistry Paper 1 2025 Mock Exam with Marking Scheme.

  It is a KCSE Chemistry (Theory) Paper 1 (233/1) trial examination.

  • Duration: 2 Hours
  • Number of Questions: 26 (Questions 1–26)
  • Marking Scheme: The marking scheme is in a different document.

  It covers the following topics:

  • Atomic structure and electronic arrangement (mass number, neutrons, group and period)
  • Reactions of metals with steam (magnesium and steam) and industrial uses of products
  • Gas calculations at STP (molar gas volume) and diffusion of gases
  • Qualitative analysis of ions (precipitation and amphoteric behaviour of zinc compounds)
  • Solubility and crystallisation calculations (cooling a saturated salt solution)
  • Periodic trends (ionisation energy, atomic/ionic radius, boiling point comparisons)
  • Composition of air practical (experiment using phosphorus to investigate active part of air)
  • Extraction and purification of metals (copper from copper pyrites; electrolytic refining; Faraday calculations)
  • Separation techniques (miscible vs immiscible liquid mixtures)
  • Radioactivity (half-life calculations)
  • Energetics and bond energies (using ∆H to determine bond energy values)
  • Industrial processes (manufacture of nitric(V) acid and uses)
  • Chemical bonding (dot-and-cross diagrams; comparing boiling points of compounds)
  • Chlorine and bleaching (formation of bleaching agents and water purification roles)
  • Polymers (natural polymers and condensation polymers such as terylene and its monomers)
  • Preparation of salts (preparing solid sodium sulphate from acid and alkali)
  • Empirical formula and percentage composition calculations
  • Hydrogen sulphide (reactions/observations and laboratory preparation and collection of a dry sample)
  • Chemical equilibrium (Le Chatelier’s principle; chromate/dichromate equilibrium; temperature effects)
  • Thermochemistry experiments (molar enthalpy/heat of displacement determination)
  • Solutions and moles (number of ions in solution; gas volume from reactions)
  • Rates of reaction (effect of temperature and ways of measuring rate)
  • Solvay process (steps in manufacture of sodium carbonate and softening hard water)
  • Group trends and structure-property comparisons (melting points, reactivity)
  • Organic chemistry (alkynes; laboratory preparation of ethyne; addition reactions)
  • Redox and electrochemistry (oxidation numbers; electrolysis of molten sodium chloride)
• Category:

  Mock Past Papers
• Level:

  Form 4
• Subject:

  CHEMISTRY

Enter your details below to initiate a payment using MPESA.