A Review of Chemistry Paper 2 (233/2) KCSE 2013: Detailed Analysis and Explanations
In this review, we will be discussing the content of the Chemistry Paper 2 (233/2) from the KCSE 2013 examination. The paper consists of various questions covering topics such as atomic radius, moles, heat of formation, electrolysis, acids and bases, radioactivity, and organic compounds.
The first question addresses atomic radius, explaining that R has the largest atomic radius with the weakest nuclear attraction. It also mentions that the atomic radius decreases across a period due to an increase in nuclear attraction. The question goes on to calculate the moles and mass of a substance, providing step-by-step calculations.
The second question focuses on the properties of different oxides. It asks about the oxide that forms a basic ionic bond, the oxide that is gaseous and forms a neutral solution, and the oxide that is solid at room temperature and acidic with a covalent bond. The correct answers are provided along with brief explanations.
Moving on to the third question, it discusses the concept of heat of formation and provides the definition. It also provides the values of heat of formation for two different reactions and asks for the overall heat of formation. The calculations are explained in detail.
Next, the fourth question deals with electrolysis. It asks about the process that takes place during electrolysis of sodium chloride solution using a diaphragm cell. The correct answers are given, including the migration of ions and the products formed at the cathode and anode. The question also mentions various applications of electrolysis, such as glass making and paper manufacture.
The fifth question focuses on acids and bases. It asks about testing the acidity of sodium sulphate and sodium hydrogen sulphate solutions using litmus paper or adding a solid carbonate. The correct answers are provided with explanations. It also asks for the steps involved in the preparation of lead(II) sulphate from lead nitrate and sodium sulphate.
Moving on to the sixth question, it discusses radioactive decay and its effects. It asks about the difference between a proton and a neutron, the process of radioactive decay, and the consequences of exposure to radioactive substances. The correct answers are given, emphasizing genetic mutation, death, and the risk of cancer.
Lastly, the seventh question deals with organic compounds. It asks about the names and structures of various compounds, including propanoic acid, pent-1-ene, but-1-yne, and ethane. It also asks for the preparation of a compound using a reaction with sodium hydroxide.
In conclusion, the Chemistry Paper 2 (233/2) from the KCSE 2013 examination covers a wide range of topics in chemistry. The questions are well-structured and cover important concepts. The answers provided are detailed and explain the reasoning behind each response. Overall, this paper is a valuable resource for students studying chemistry and preparing for examinations.
