1. Which of the following determines that a chemical reaction has not taken place ?
A. Change in size
B. Evolution of a gas
C. Change in colour
D. Change in state
ANSWER:D.Change in state
SOLUTION : A chemical reaction involves a permanent change where new substances are formed, different from the original substance. If there’s no new substance formed, or the chemical composition of the original substance remains unchanged, then a chemical reaction likely hasn’t taken place. No new substance formed and No change in chemical composition.
2. In which chemical reaction do bonds or ions exchange between two compounds to form different compounds?
A. Substitution reaction
B. Dual displacement reaction
C. Redox reaction
D. Direct combination reaction
ANSWER:B.Dual displacement reaction
SOLUTION:Those reactions in which two compounds react by an exchange of ions to form two new compounds are called double displacement reactions. In double displacement reactions, the positive ions exchange negative ion partners.
3. Which of the following chemical reactions is always endothermic in nature?
A. Combustion reaction
B. Decomposition reaction
C. Displacement reaction
D. Combination reaction
ANSWER : B.Decomposition reaction
SOLUTION: Decomposition reactions are generally endothermic because they require energy to break the bonds between atoms.
4. The chemical reaction in which heat is released is called ________.
A. Exothermic
B. Combination
C. Endothermic
D. Decomposition
ANSWER:A.Exothermic
SOLUTION:Therefore the chemical reaction in which heat is released is called an exothermic reaction.
5. A reaction in which one or more molecules of a substance are interconnected through a double or triple bond is called ?
A. Esterification
B. Addition reactions
C. Functional group
D. Water decomposition or saponification
ANSWER:B.Addition reactions
SOLUTION:”addition reaction”.
6. Which of the following reactions is an example of an endothermic reaction?
A. Dissolution of sodium hydroxide in water
B. Decomposition of ferrous sulphate
C. Dilution of sulphuric acid
D. Burning of natural gas
ANSWER:B.Decomposition of ferrous sulphate
SOLUTION:The decomposition of ferrous sulfate is an example of an endothermic reaction because it absorbs heat. Other examples of endothermic reactions include: Melting ice cubes, Converting frost to water vapor, and Dissolving ammonium chloride in water.
7. What is known as the merging of an acid or alkali in water ?
A. Decomposition reaction
B. Exothermic reaction
C. Neutral reaction
D. Endothermic reaction
ANSWER:B.Exothermic reaction
SOLUTION :
The reaction between an acid and a base results in a salt and water as products. This reaction is called Neutralisation reaction. An acid readily combines with a base in this process, while giving out heat energy. This type of reaction is called Exothermic reactions.
8. ___________ It is a process in which acids and bases combine to form salts and water.
A. Neutralization
B. Electrical decomposition
C. Distillation
D. Hydrolysis
ANSWER: A.Neutralization
SOLUTION:The process in which acids and bases combine to form salts and water is called a neutralization reaction
9. Which of the following is an exothermic process ?
A. Sublimation of Camphor
B. Reaction of water with quick lime
C. Evaporation of water
D. All of the options
ANSWER:B.Reaction of water with quick lime
SOLUTION: Dilution of an acid and Reaction of water with Quicklime are exothermic processes.
10. The reaction of sodium sulphate and barium chloride solutions is an example of ________.
A. Single displacement reactions
B. Exothermic reaction
C. Double displacement reaction
D. Endothermic reaction
ANSWER: C.Double displacement reaction
SOLUTION:
The chemical reaction between barium chloride and sodium sulphate is an example of a double displacement reaction.