In CBSE Class 10 Science Paper, Students will have to answer some questions based on Assertion and Reason. There will be a few questions based on case studies and passage based as well. In that, a paragraph will be given, and then the MCQ questions based on it will be asked.
Here, we have provided case based/passage based questions for Class 10 Science Chapter 1 Chemical Reactions and Equations.
Case Study/Passage Based Questions
Corrosion is the phenomenon of deterioration of surface of metal in presence of air and moisture. It is a natural process and in the presence of a moist atmosphere, chemically active metals get corroded. This is an oxidation reaction. Rusting is the process where iron corrodes due to exposure to the atmosphere. The main circumstance of corrosion occurs with iron because it is a structural material in construction, bridges, buildings, rail transport, ships, etc. Aluminium is also an important structural metal, but even aluminium undergoes oxidation reactions. However, aluminium doesn’t corrode or oxidize as rapidly as its reactivity suggests. Copper (Cu) corrodes and forms a basic green carbonate.
(i) What is rusting?
AnswerAnswer: The deterioration of surface of iron in presence of air and moisture is called rusting.
(ii) Which two metals do not corrode easily?
AnswerAnswer: Gold and Platinum
(iii) Write the chemical name of the compound formed on corrosion of silver.
AnswerAnswer: Silver sulphide, Ag2S
(iv) Corrosion is
(a) a redox reaction
(b) a reduction reaction
(c) a displacement reaction
(d) an oxidation reaction
Oxidation is the process of gaining of oxygen, or losing of hydrogen. Reduction is the process of losing of oxygen or gaining of hydrogen. The substance which undergoes oxidation is the reducing agent while the substance which undergoes reduction is known as the oxidising agent. Oxidation and reduction always take place together and these type of reactions are known as redox reactions. Some of the examples of redox reactions are given below:
(i) Give two examples of oxidation reaction from your everyday life.
AnswerAnswer: Corrosion and Rancidity
(ii) Write the oxidising agent in the reaction III and VI.
AnswerAnswer: CuSO4 in (III) and CuO in (VI)
(iii) Which of the following is an oxidising agent?
(b) Alkaline KMnO4
(c) Acidified K2Cr2O7
(d) Both (b) and (c)
(iv) Out of oxidation and reduction, which reaction takes place at anode?