Q.1 The shiny finish of wall after white wash is because of:
a) Calcium oxide
b) Calcium hydroxide
c) Calcium Carbonate
d) Calcium phosphate
Answer: c) Calcium Carbonate
Explanation: When whitewash (which contains calcium hydroxide) is applied to walls, it reacts with carbon dioxide in the air to form calcium carbonate, which gives a shiny finish.
Q.2 Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is:
a) 1:1
b) 2:1
c) 4:1
d) 1:2
Answer: b) 2:1
Explanation: Water (Hâ‚‚O) decomposes into hydrogen (Hâ‚‚) and oxygen (Oâ‚‚) in a 2:1 mole ratio during electrolysis.
Q.3 Which of the following statements about the given reaction are correct:
3Fe(s) + 4H₂O(g) → Fe₃O₄(s) + 4H₂(g)
i) Iron metal is getting oxidized
ii) Water is getting reduced
iii) Water is acting as reducing agent
iv) Water is acting as oxidizing agent
a) (i), (ii) and (iii)
b) (iii) and (iv)
c) (i), (ii) and (iv)
d) (ii) and (iv)
Answer: c) (i), (ii) and (iv)
Explanation: Iron is oxidized as it loses electrons, water is reduced as it gains electrons, and water acts as an oxidizing agent.
Q.4 In order to prevent the spoilage of potato chips, they are packed in plastic bags containing the gas:
a) Clâ‚‚
b) Oâ‚‚
c) Nâ‚‚
d) Hâ‚‚
Answer: c) Nâ‚‚
Explanation: Nitrogen (Nâ‚‚) is an inert gas that prevents oxidation and spoilage of potato chips.
Q.5 The process of respiration is:
a) an oxidation reaction which is endothermic
b) a reduction reaction which is exothermic
c) a combination reaction which is endothermic
d) an oxidation reaction which is exothermic
Answer: d) an oxidation reaction which is exothermic
Explanation: Respiration involves the oxidation of glucose to produce energy, making it an exothermic reaction.
Q.6 Burning of Methane is an example of:
I. Exothermic reaction
II. Combustion reaction
III. Decomposition reaction
a) I only
b) II only
c) I and II
d) I and III
Answer: c) I and II
Explanation: Burning methane (CHâ‚„) is both an exothermic and a combustion reaction, as it releases heat and involves burning in the presence of oxygen.
Q.7 A solution of substance X is used for white washing, the substance X is:
a) Calcium oxide
b) Calcium hydroxide
c) Calcium carbonate
d) Calcium chloride
Answer: b) Calcium hydroxide
Explanation: Calcium hydroxide (also known as slaked lime) is used in whitewashing.
Q.8 When iron nails are dipped into Copper Sulphate solution the colour of Copper Sulphate solution changes from:
a) Green to blue
b) Blue to green
c) Green to colourless
d) Blue to colourless
Answer: b) Blue to green
Explanation: Iron displaces copper from copper sulfate solution, forming iron sulfate, which has a greenish color.
Q.9 The given Chemical reaction is an example of:
Zn + CuSO₄ → ZnSO₄ + Cu
a) Combination reaction
b) Displacement reaction
c) Decomposition reaction
d) Double displacement reaction
Answer: b) Displacement reaction
Explanation: Zinc displaces copper from copper sulfate, demonstrating a single displacement reaction.
Q.10 The balanced equation for the given chemical reaction is:
Hydrogen + Chlorine → Hydrogen Chloride
a) H₂ + Cl₂ → 2HCl
b) HCl → HCI
c) H₂ + Cl₂ → HCI
d) none of the above
Answer: a) H₂ + Cl₂ → 2HCl
Explanation: Two hydrogen atoms react with two chlorine atoms to form two molecules of hydrogen chloride.
Other Related Questions For Practicing Before the Exam
- MCQ Test for Chemical Reactions and Equations Class 10
- Support MCQs Answer: Chemical Reactions and Equations Class 10
- Give an example of a double displacement reaction
- Name reducing agent in the given chemical reaction: 3MnO2 + 4Al → 3Mn + 2Al2O3
- Name the brown coloured gas evolved when lead nitrate crystals are heated in a dry test-tube
- Give reasons: Silver chloride is stored in dark-colored bottles.
- What changes do you observe in iron nails and the color of the copper sulphate solution if iron nails are dipped in CuSOâ‚„ solution for some time?
- Identify the chemical change: Melting of ice or conversion of milk into curd.
- Why is respiration considered an exothermic reaction?
- Why do copper vessels lose shine when exposed to air?
- Potato chips manufacturers fill the packet of chips with nitrogen gas. Why?
- Why do we store silver chloride in dark coloured bottles in labs?
- Write chemical equations of a double displacement reaction
- N₂ + 3H₂ → 2NH₃, name the type of reaction.
- What happens when milk is left open at room temperature during summer?
- What happens when quicklime is added to water?
- Define combination reaction. Give two examples of combination reactions which are exothermic in nature.
- What is decomposition reaction? Explain with the help of an example.
- Name and state the law which is kept in mind when we balance a chemical equation
- Give one example of each: (a) Chemical reaction showing evolution of gas:
- What is rancidity? Write two ways by which it can be prevented.
- What are two conditions which promote corrosion?
- A small amount of Ferrous sulphate is heated in hard glass tube.
- What happens when Zn strip is dipped in CuSO2 solution?
- What is a redox reaction? Write down a chemical reaction representing it.
- In electrolysis of water: Name the gas collected at cathode and anode
- In the reaction: CuO(s) + H2(g) → Cu(s) + H2O (g)
- Give reasons: (a) White silver chloride turns grey in sunlight
- Compound ‘X’ decomposes to form compound ‘Y’ and COâ‚‚ gas. Compound Y is used in the manufacturing of cement.
- A metal salt MX, when exposed to light, splits up to form metal M and gas Xâ‚‚. Metal M is used to make ornaments whereas gas Xâ‚‚ is used in making bleaching powder. The salt MX is used in black & white photography.