CBSE Class 10 Science Chemical reactions and equations Sure Shot Questions Set 04

Question. Which of the following statements is incorrect ?
(a) In oxidation, oxygen is added to a substance.
(b) In reduction, hydrogen is added to a substance.
(c) Oxidizing agent is oxidized.
(d) Reducing agent is oxidized.
Answer: (c) Oxidizing agent is oxidized.

Question. Which of the statements about the following reactions is correct ?
\( ZnO + CO \to Zn + CO_{2} \)
(a) \( ZnO \) is being oxidized.
(b) \( CO \) is being reduced.
(c) \( CO_{2} \) is being oxidized.
(d) \( ZnO \) is being reduced.
Answer: (d) \( ZnO \) is being reduced.

Question. A substance which oxidises itself and reduces other is known as
(a) Oxidising agent
(b) Reducing agent
(c) Both of these
(d) None of the options
Answer: (b) Reducing agent

Question. In the reaction \( PbO + C \to Pb + CO \)
(a) \( PbO \) is oxidised.
(b) \( C \) acts as oxidising agent.
(c) \( C \) acts as reducing agent.
(d) This reaction does not represent redox reaction
Answer: (c) \( C \) acts as reducing agent.

Question. The following reaction coordinate diagram represents
(a) an exothermic reaction.
(b) an endothermic reaction.
(c) a reaction that is neither endothermic nor exothermic.
(d) a reaction in which a catalyst is used.
Answer: (a) an exothermic reaction.

Question. The process of oxidation involves
(a) the absorption of hydrogen atoms.
(b) the absorption of electrons.
(c) the release of electrons.
(d) neither absorption nor release of electrons.
Answer: (c) the release of electrons.

Question. Rusting of an iron is an example of
(a) Reduction
(b) Ionization
(c) Oxidation
(d) Dissociation
Answer: (c) Oxidation

Question. In the reaction \( 2MnO_{2} + 4Al \to 3Mn + 2Al_{2}O_{3} \), the oxidising agent is
(a) \( MnO_{2} \)
(b) \( Al \)
(c) \( Al_{2}O_{3} \)
(d) \( Mn \)
Answer: (a) \( MnO_{2} \)

Question. Which of the following does not corrode when exposed to the atmosphere ?
(a) Iron
(b) Copper
(c) Gold
(d) Silver
Answer: (c) Gold

Question. The oxidizing agent in the lead storage battery is
(a) \( Pb \)
(b) \( PbO_{2} \)
(c) \( PbSO_{4} \)
(d) \( H_{2}SO_{4} \)
Answer: (b) \( PbO_{2} \)

Question. When carbon dioxide gas is passed through lime water,
(a) calcium hydroxide is formed.
(b) white precipitate of \( CaO \) is formed.
(c) white precipitate of \( CaCO_{3} \) is formed.
(d) colour of lime water disappears.
Answer: (c) white precipitate of \( CaCO_{3} \) is formed.

Question. In the equation, \( NaOH + HNO_{3} \to NaNO_{3} + H_{2}O \) nitric acid is acting as
(a) an oxidising agent
(b) an acid
(c) a reducing agent
(d) a dehydrating agent
Answer: (b) an acid

Question. \( Zn^{2+}(aq) + 2e^{-} \to Zn(s) \). This is
(a) Oxidation
(b) Reduction
(c) Redox reaction
(d) None of the options
Answer: (b) Reduction

Question. Consider the reaction \( Zn + Cu^{2+} \to Zn^{2+} + Cu \). With reference to the above, which one of the following is the correct statement ?
(a) \( Zn \) is reduced to \( Zn^{2+} \).
(b) \( Zn \) is oxidised to \( Zn^{2+} \).
(c) \( Zn^{2+} \) is oxidised to \( Zn \).
(d) \( Cu^{2+} \) is oxidised to \( Cu \).
Answer: (b) \( Zn \) is oxidised to \( Zn^{2+} \).

Question. In the reaction \( PCl_{3} + Cl_{2} \to PCl_{5} \)
(a) \( PCl_{3} \) is acting as reductant.
(b) \( Cl_{2} \) is acting as reductant.
(c) Both \( PCl_{3} \) and \( Cl_{2} \) are acting as reductant.
(d) Both \( PCl_{3} \) and \( Cl_{2} \) are acting as oxidant.
Answer: (a) \( PCl_{3} \) is acting as reductant.

Question. The correct formula of rust is
(a) \( Fe_{2}O_{3} \)
(b) \( Fe_{3}O_{4} \)
(c) \( Fe_{2}O_{3} \cdot xH_{2}O \)
(d) \( Fe_{3}O_{4} \cdot xH_{2}O \)
Answer: (c) \( Fe_{2}O_{3} \cdot xH_{2}O \)

Question. Antioxidants are
(a) hydrating agents
(b) dehydrating agents
(c) oxidizing agents
(d) reducing agents
Answer: (d) reducing agents

Question. The rate of a chemical reaction can be increased by adding a
(a) catalyst
(b) pigment
(c) reactant
(d) product
Answer: (a) catalyst

Question. When lead nitrate reacts with potassium iodide, yellow precipitate of
(a) \( PbI_{2} \) is formed
(b) \( KNO_{3} \) is formed
(c) \( Pb(NO_{3})_{2} \) is formed
(d) \( PbIO_{3} \) is formed
Answer: (a) \( PbI_{2} \) is formed

Question. Among the following metals, which corrodes negligibly ?
(a) Gold
(b) Platinium
(c) Palladium
(d) All of the options
Answer: (d) All of the options