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1. The chemical formula of magnesium oxide is ______.

A. MgO2 B. Mg(OH)2 C. Mg2O D. MgO

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2. What happens when lead nitrate reacts with potassium iodide?

A. Yellow ppt of lead iodide and potassium nitrate will be produced B. Evolution of gas will occur C. They will not react D. A large amount of hydrogen will be released

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3. Sodium and chlorine are reacted, and as a result, sodium chloride is formed, which is also called table salt. What option gives the reactants and products of the reaction?

A. Reactants – sodium and chlorine, products – sodium chloride B. Reactants – tables salt, products – sodium and chlorine C. Reactants – sodium, products – chlorine D. Reactants – sodium and table salt, products – chlorine

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4. A researcher adds barium hydroxide to hydrochloric acid to form a white-coloured barium chloride. Which of the following option gives the balanced chemical equation of the reaction?

A. 2HCl + Ba(OH)2 → BaCl2 + 2HOH B. HCl + Ba(OH)2 → BaCl2 + 2HOH C. HCl + 2Ba(OH) → 2BaCl2 + 2HOH + O2 D. 2HCl + Ba(OH)2 → BaH2 + 2HCl + O2

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5. Which of the following reactions is used in black-and-white photography?

A. Decomposition Reaction B. Displacement reaction C. Combination Reaction D. Oxidation reaction

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6. Which of the following reaction can also be termed a thermal decomposition reaction?

A. Combination reaction B. Double displacement reaction C. Decomposition reaction D. Displacement reaction

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7. Give the ratio in which hydrogen and oxygen are present in water by volume.

A. 1:2 B. 1:8 C. 1:1 D. 2:1

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8. A student performs an experiment to form aluminum chloride from aluminum and chlorine. Which of the following option gives the chemical equation of the reaction?

A. 2Al + Cl2 → 2AlCl B. 3Al + 3Cl2 → 3AlCl3 C. 2Al + 3Cl2 → 2AlCl3 D. Al + Cl2 → AlCl2

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9. From the following, which one is an example of a chemical reaction?

A. Formation of curd B. Grapes get fermented C. All of the above D. Breakdown of food

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10. One of the following processes does not involve a chemical reaction, that is:

A. Digestion of food in your stomach B. Melting of candle wax when heated C. Burning of candle wax when heated D. Ripening of banana

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11. A student wrote a chemical equation of the reaction between carbon monoxide and hydrogen as, CO2 + 2H2 → CH3OH. How can the reaction be classified?

A. The reaction is an example of a combination reaction as a compound separates into two compounds. B. The reaction is an example of a combination reaction as two compounds react to form a single compound. C. The reaction is an example of a decomposition reaction as a compound dissociates into two compounds. D. The reaction is an example of a decomposition reaction as two compounds react to form a single compound.

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12. Which of the following shows an oxidation reaction?

A. None of the above B. Gain of oxygen C. Gain of hydrogen D. Loss of oxygen

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13. A student adds lead and silver to two different test tubes containing an equal amount of copper sulphate solution. The student observes that the colour of the solution in the test tube with lead changes. What explains the change in the colour of the solution?

A. A combination reaction takes place as lead combines with sulphate in the solution. B. A double displacement reaction takes place as copper dissociates from sulphate and lead combines with sulphate in the solution. C. A decomposition reaction takes place as copper dissociates from sulphate in the solution. D. A displacement reaction takes place as lead replaces copper from the solution.

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14. The chemical reaction between potassium chloride and silver nitrate is given by the chemical equation, AgNO3 + KCl → AgCl + KNO3. What can be inferred from the chemical equation?

A. Silver nitrate and potassium undergo a decomposition reaction to form silver chloride and potassium nitrate B. Silver nitrate and potassium undergo a displacement reaction to form silver chloride and potassium nitrate C. Silver nitrate and potassium undergo a combination reaction to form silver chloride and potassium nitrate D. Silver nitrate and potassium undergo a double displacement reaction to form silver chloride and potassium nitrate