Question Paper
Class / Subject: Class 10 (CBSE) · Science
Chapter: Chapter 1 — Chapter 1: Chemical Reactions and Equations
Time Allowed: 15 minutes
Max Marks: 6
1. A reaction where two substances combine to form one product is called a: [1]
(A) combination reaction
(B) decomposition reaction
(C) displacement reaction
(D) double displacement reaction
2. Rusting of iron (4Fe+3O₂→2Fe₂O₃) is an example of a: [1]
(A) combination reaction
(B) decomposition reaction
(C) displacement reaction
(D) neutralisation
3. A double displacement reaction is often identified by: [1]
(A) formation of a precipitate
(B) release of oxygen only
(C) no visible change
(D) change in mass
4. A balanced equation ensures: [1]
(A) equal atoms of each element on both sides
(B) equal number of molecules on both sides
(C) equal number of compounds only
(D) equal mass of only one element
5. When balancing equations, we adjust: [1]
(A) coefficients only
(B) subscripts only
(C) both coefficients and subscripts
(D) neither
6. The balanced form of H₂+O₂→H₂O is: [1]
(A) 2H₂+O₂→2H₂O
(B) H₂+O₂→H₂O
(C) H₂+2O₂→H₂O
(D) 2H₂+2O₂→2H₂O