Summary

• Description:

  The PDF document comprises the Chemistry Paper 3 (Practical) Kenya High School 2024 Mock Exam as a KCSE Trial Exam. The file contains both the question paper for the candidate and the confidential instructions for laboratory preparation.

  The practical examination consists of three compulsory questions to be completed within a duration of 2 hours. It is designed to test a range of practical skills, including accurate measurement, titration, dilution, data recording, graphical analysis, and chemical identification through observation and inference.

  The paper includes the following experiments:

  • Question 1: Titration and Dilution. This experiment involves two main procedures. First, the candidate must prepare a dilute solution of sodium hydroxide (Solution C) from a provided stock solution (2.0M NaOH). Second, the candidate uses this diluted solution to titrate against a solution of sulphuric(VI) acid (Solution A) using phenolphthalein indicator. The goal is to determine the concentration of the sulphuric acid solution through stoichiometric calculations based on the titration results.
  • Question 2: Thermochemistry. This experiment aims to determine the molar enthalpy of neutralization. Candidates are required to measure the temperature changes that occur when successive portions of 2.0M sodium hydroxide are added to a fixed volume of 2.0M hydrochloric acid. The results are used to plot a graph of temperature versus volume of NaOH added, from which the maximum temperature change is determined and used to calculate the molar enthalpy.
  • Question 3: Qualitative Analysis. This question requires the candidate to perform a series of chemical tests on an unknown substance, Solid N (identified as Aluminium Sulphate, Al₂(SO₄)₃, in the confidential instructions), to identify its constituent ions. The tests include reacting the dissolved solid with sodium hydroxide, ammonia solution, potassium iodide, and acidified barium nitrate, and recording the observations and inferences to identify the cation and anion present.
• Category:

  Mock Past Papers
• Level:

  Form 4
• Subject:

  CHEMISTRY

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