Preparing for the Joint Admissions and Matriculation Board (JAMB) examination requires thorough studying and practice.
One aspect that students often focus on is familiarizing themselves with past questions and answers, as JAMB has been known to repeat certain questions.
In this article, we have compiled a list of randomly selected JAMB Chemistry questions that have appeared in previous exams.
By studying and understanding these questions, you can enhance your chances of scoring well in the Chemistry section of the JAMB examination.
- What is the shape of a molecule of CCl4? Answer: B (Tetrahedral)
Explanation:
The molecule CCl4, also known as carbon tetrachloride, has a tetrahedral shape. This means that the carbon atom is located at the center of the molecule, with four chlorine atoms arranged symmetrically around it.
- A sample of gas with an initial volume of 2.5 dm3 is heated and then allowed to expand to 7.5 dm3 at constant pressure. What is the ratio of the final temperature to the initial absolute temperature? Answer: A (3:1)
Explanation:
According to Charles’ Law, when the pressure of a gas is kept constant, the ratio of the volume to the absolute temperature remains constant. In this case, the initial volume is 2.5 dm3, and the final volume is 7.5 dm3, which gives a ratio of 3:1 for the final temperature to the initial absolute temperature.
- 6g of Mg was added to 100cm3 of 1 moldm3 H2SO4. What mass of Mg remained undissolved? (Mg = 24) Answer: C (3.6g)
Explanation:
To calculate the mass of Mg that remained undissolved, we need to determine the amount of Mg that reacted with the H2SO4. Since the molar mass of Mg is 24 g/mol and the volume of the H2SO4 solution is 100 cm3 (which is equal to 0.1 dm3), we can calculate the number of moles of Mg used in the reaction. Subtracting this from the initial 6g of Mg will give us the mass of Mg that remained undissolved, which is 3.6g.
- Which of the following will act as both oxidizing agents and reducing agents? Answer: D (SO2)
Explanation:
Sulfur dioxide (SO2) can act as both an oxidizing agent and a reducing agent, depending on the reaction conditions. In certain reactions, SO2 can gain or lose electrons, making it capable of undergoing oxidation or reduction.
- A metal which can be used as a sacrificial anode for preventing the corrosion of an iron pipe is: Answer: C (Silver)
Explanation:
Silver is a metal that can be used as a sacrificial anode to prevent the corrosion of an iron pipe. Sacrificial anodes are more reactive metals that are intentionally connected to a less reactive metal, such as iron, to protect it from corrosion by sacrificing themselves.
Conclusion
Preparing for the JAMB Chemistry section can be challenging, but by studying past questions and understanding the concepts behind them, you can increase your chances of success.
The questions provided in this article are a sample of the types of questions that have been repeated in previous JAMB examinations.
However, it’s important to note that the JAMB exam is dynamic, and questions may vary from year to year.
Therefore, it is advisable to study a wide range of topics and practice extensively to be well-prepared for the actual exam. Good luck with your JAMB preparation!