Lakhmir Singh & Manjit Kaur Test: Chemical Reactions & Equations - Class 10 MCQ

• A neutralization reaction can be defined as a chemical reaction in which an acid and base quantitatively react together to form salt and water as products. In a neutralization reaction, there is a combination of H⁺ ions and OH^– ions that form water.

• A double displacement reaction is a type of reaction in which two reactants exchange ions to form two new compounds. Double displacement reactions typically result in the formation of a product that is a precipitate. 
  Double displacement reactions take the form: AB + CD → AD + CB

• Reaction with the absorption of energy is called an endothermic reaction.
  In reaction (i) Sodium Bicarbonate needs the energy to form sodium carbonate, water and carbon dioxide. 
  Hence it is an endothermic reaction.
• Reaction with the release of energy is called an exothermic reaction.
  In the reaction (ii) on the burning of magnesium wire, magnesium oxide is formed by the release of energy in the form of heat and light.
  Hence it is an exothermic reaction.

Aluminium being more reactive displaces the manganese metal and forms a new compound. Hence it is a displacement reaction.

The heat is also released along with the formation of products, hence it is an exothermic reaction.

Addition of Oxygen to a Substance or removal of Hydrogen from a substance is called Oxidation.

Removal of Oxygen from a substance or addition of Hydrogen to a substance is called Reduction.

Oxygen is added to C, and it gets oxidized to CO 2 .

Therefore, C gets oxidized .

Oxygen is removed from PbO, and it gets reduced to Pb.

Therefore, PbO gets reduced.

Therefore, (c) and (d) are correct.

And, (i) and (ii) are incorrect .

In the given reaction, Ferric oxide is getting converted to Iron while aluminium is getting oxidized to aluminium oxide. Thus, iron is going from a combined state to a free state whereas aluminium is going from a free state to the combined state. Such a reaction is called displacement reaction as in displacement reactions, the more reactive metal (Al in this case) displaces the less reactive metal (Fe in this case) from its compound.

When metals react with acids, H2 gas is evolved along with the formation of the respective salt of metal.
Fe(s) + 2HCl(aq) → FeCl₂(s) + H₂(g) ↑

A decomposition reaction is a reaction in which a compound breaks down into two or more simpler substances. The general form of a decomposition reaction is AB→A+B. Most decomposition reactions require an input of energy in the form of heat, light, or electricity.

In this reaction, two new substances lead iodide, and sodium nitrate are formed by an interchange of radicals in lead nitrate and sodium iodide.

Zn + CuSO₄ → ZnSO₄ + Cu blue colourless.