Q1. A substance ‘X’ is used in white-washing and is obtained by heating limestone in the absence of air. The substance ‘X’ is
Q2. Select the oxidising agent for the following reaction:
H2S + I2 → 2HI + S
Q3. A substance added to food containing fats and oils is called:
Q4. The condition produced by aerial oxidation of fats and oils in foods marked by unpleasant smell and taste is called:
Q5. When SO2 gas is passed through saturated solution of H2S, which of the following reaction occurs?
(A) SO2 + 2H2S → 2H2O + 3S
(B) SO2 + 2H2S → H2O + 3S
(C) SO2 + H2S → H2O + S
(D) SO2 + H2O → SO3 + H2
Q6. What are the products formed when iron filings are heated with dilute hydrochloric acid?
(A) Fe (III) chloride and water
(B) Fe (II) chloride and water
(C) Fe (II) chloride and hydrogen gas
(D) Fe (III) chloride and hydrogen gas
Q7. A student performs an experiment to form aluminium chloride from aluminium and chlorine. Which options gives the balanced chemical equation of the reaction?
(A) 3Al + 3Cl2 → 3AlCl3
(B) 2Al + Cl2 → 2AlCl
(C) 2Al + 3Cl2 → 2AlCl3
(D) Al + Cl2 → AlCl2
Q8. A researcher adds barium hydroxide to hydrochloric acid to form a white coloured barium chloride. Which option gives the balanced chemical equation of the reaction?
(A) HCl + 2Ba(OH) → 2BaCl2 + 2H2O + O2
(B) 2HCl + Ba(OH)2 → BaCl2 + 2H2O
(C) 2HCl + Ba(OH)2 → BaH2 + 2HCl + O2
(D) 2HCl + Ba(OH)2 → BaH2 + 2HCl + O2
Q9. A student learns that some products are formed as a result of combining two compounds while
some products are formed as a result of dissociation of two compounds. Two reactions are:
Reaction P – CaO + SO3 → CaSO4
Reaction Q – ZnCO3 → ZnO + CO2
Which reaction is an example of a combination reaction and a decomposition reaction?
(A) Both the reactions are examples of a decomposition reaction.
(B) P is an example of a decomposition reaction while reaction Q is an example of a combination
(C) Reaction P is an example of a combination reaction while reaction Q is an example of a decomposition reaction.
(D) Both the reactions are examples of combination reaction.
Q10. 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 displacement reaction takes place as lead replaces copper from the solution.
(B) Decomposition reaction takes place as copper dissociates from sulphate in the solution.
(C) A double displacement reaction takes place as copper dissociates from sulphate and lead combines with sulphate in the solution.
(D) A combination reaction takes place as lead combines with sulphate in the solution.
Q11. The chemical reaction between potassium chloride and silver nitrate is given by the chemical equation. What can be inferred from the chemical equation? KCl + AgNO3 → AgCl + KNO3
(A) Silver nitrate and potassium undergo a combination reaction to form silver chloride and potassium nitrate.
(B) Silver nitrate and potassium undergo a decomposition reaction to form silver chloride and potassium nitrate.
(C) Silver nitrate and potassium undergo a displacement reaction to form silver chloride and potassium nitrate.
(D) Silver nitrate and potassium chloride undergo double displacement reaction to form silver chloride and potassium nitrate.
Q12. A student notices that the bread kept out has a green coloured coating over it after a few days. What explains the reason for the student’s observation?
(A) The oils in the bread reduces and cause the change in the colour of the bread.
(B) Bread comes in contact with atmospheric moisture and corrodes.
(C) The oils in the bread oxidises and causes rancidity.
(D) Comes in contact with the atmospheric nitrogen and a layer deposits over it.
Q13. Calcium oxide reacts vigorously with water to produce slaked lime.
CaO (s) + H2O (l) → Ca(OH)2 (aq)
This reaction can be classified as:
(A) Combination reaction
(B) Exothermic reaction
(C) Endothermic reaction
(D) Oxidation reaction
Which of the following is a correct option?
(A) (A) and (C)
(B) (C) and (D)
(C) (A), (C) and (D)
(D) (A) and (B)
Q14. When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate or copper sulphide is obtained and the sulphuric acid so formed remains in the solution.
The reaction is an example of a :
(A) Combination reaction
(B) Displacement reaction
(C) Decomposition reaction
(D) Double displacement reaction
Q15. In which of the following the identity of initial substance remains unchanged?
(A) Curdling of milk
(B) Formation of crystals by process of crystallisation
(C) Fermentation of grapes
(D) Digestion of food