NABTEB Chemistry Past Questions And Answers (Objective and Theory)

Chemistry questions suitable for the NABTEB examination:

Section A (Objective)

Question: What is the role of a catalyst in a chemical reaction?

A) Initiating the reaction

B) Increasing reaction rate

C) Consuming reactants

D) Producing heat

Answer: B) Increasing reaction rate

Question: Identify the gas evolved when calcium carbonate reacts with hydrochloric acid.

A) Oxygen

B) Carbon dioxide

C) Hydrogen

D) Nitrogen

Answer: B) Carbon dioxide

Question: Which of the following is an example of a redox reaction?

A) NaCl + H₂O → NaOH + HCl

B) 2H₂ + O₂ → 2H₂O

C) 2Na + Cl₂ → 2NaCl

D) FeSO₄ + 2NaOH → Fe(OH)₂ + Na₂SO₄

Answer: C) 2Na + Cl₂ → 2NaCl

Question: What is the chemical formula for acetic acid?

A) HCl

B) H₂SO₄

C) CH₃COOH

D) NaOH

Answer: C) CH₃COOH

Question: In the periodic table, which group do alkaline earth metals belong to?

A) Group 1

B) Group 2

C) Group 17

D) Group 18

Answer: B) Group 2

Section B (Theory) –

Question: Explain the concept of chromatography in analytical chemistry, detailing its types and applications.

Answer: Chromatography is a separation technique based on the differential movement of components in a mixture. Types include gas chromatography and paper chromatography. Applications range from forensic analysis to pharmaceuticals.

Question: Discuss the principles of the Le Chatelier’s principle, emphasizing its application in predicting the effects of changes in temperature, pressure, and concentration on chemical equilibrium.

Answer: Le Chatelier’s principle states that if a system at equilibrium is subjected to a change, it will shift its position to counteract that change. It helps predict how changes impact chemical reactions.

These questions are designed to cover various aspects of chemistry, ensuring comprehensive preparation for the NABTEB examination.