Lesson - 1: Chemical reactions and equations MCQs for Class-10 Chemistry

 

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MCQs for Class-X Chemistry

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Fill in the blanks

1. Change in state, change in color, evolution of a gas and change in temperature between the reactants will determine whether ________________ takes place.

2. A chemical equation represents a _______________.

3. Chemical formula for marble is _____________.

4. _____________ are broken down to form glucose.

5. _____________ combines with oxygen in the cells of our body and provide energy.

6. Calcium oxide is called ____________________.

7. Chemical formula for limestone ___________.

8. When a decomposition reaction is carried out by heating, it is called ____________.

9. The decomposition reactions require energy either in the form of ___________, ________________, or ___________ for breaking down reactants.

10. Reactions in which energy is absorbed are known as ______________.

11. Name the chemicals used in black & white photography ____________, ____________.

12. The reaction in which the 2 reactants interchange their ions is _____________.

13. Any reaction that produces a precipitate can be called a _____________.

14. If a substance gains oxygen during reaction, it is said to be ____________.

15. If a substance loses oxygen during reaction, it is said to be ______________.

16. When a metal is attacked by substances around it such as moisture, acids, etc., this process is called        _____________.

17. When fats and oils are oxidized , they become ___________.

18. Keeping food in air tight containers help to slow down _____________.

19. The process of coating iron articles with zinc to prevent corrosion is _________________.

20. When copper is heated in the presence of oxygen, a _________ color coat is observed on copper.

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Answers for Fill in the Blanks

1. Change in state, change in color, evolution of a gas and change in temperature between the reactants will determine whether chemical reaction takes place.

2. A chemical equation represents a chemical reaction.

3. Chemical formula for marble is CaCO

₃

.

4. Carbohydrates are broken down to form glucose.

5. Glucose combines with oxygen in the cells of our body and provide energy.

6. Calcium oxide is called quick lime.

7. Chemical formula for limestone is CaCO₃.

8. When a decomposition reaction is carried out by heating, it is called thermal decomposition.

9. The decomposition reactions require energy either in the form of heat, light, or electricity for breaking down reactants.

10. Reactions in which energy is absorbed are known as endothermic.

11. Name the chemicals used in black & white photography Silver chloride and Silver bromide.

12. The reaction in which the 2 reactants interchange their ions is double displacement reaction.

13. Any reaction that produces a precipitate can be called a precipitation reaction.

14. If a substance gains oxygen during reaction, it is said to be oxidation.

15. If in a reaction, both oxidation and reduction takes place, it is said to be redox reaction.

16. When a metal is attacked by substances around it such as moisture, acids, etc., this process is called corrosion.

17. When fats and oils are oxidized , they become rancid.

18. Keeping food in air tight containers help to slow down oxidation.

19. The process of coating iron articles with zinc to prevent corrosion is galvanization.

20. When copper is heated in the presence of oxygen, a black color coat is observed on copper.

 

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