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Explain why, explosion of a firework (su...

Explain why, explosion of a firework (such as cracker) is said to be a chemical change.

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Explosion of a cracker is a chemical change because the explosive reactants are transformed into gaseous products along with heat, light and sound which cannot be reversed. Hence, it is a chemical change.
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LAKHMIR SINGH & MANJIT KAUR-PHYSICAL AND CHEMICAL CHANGES-EXERCISE
  1. State three differences between a physical change and a chemical chang...

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  2. Write a word equation to represent the process of rusting of iron. Als...

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  3. Explain why, explosion of a firework (such as cracker) is said to be a...

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  4. Explain why, melting of ice to form water is said to be a physical cha...

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  5. What is meant by crystallisation ? State its one use.

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  6. Describe how, crystals of copper sulphate are prepared.

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  7. Give example of a chemical change which occurs by the action of heat.

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  8. Give example of a physical change which occurs by the action of heat.

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  9. What is a (a) physical change, and (b) chemical change ? Give two exam...

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  10. What is meant by the rusting of iron ? State two conditions necessary ...

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  11. What happens when an iron nail is kept immersed in copper sulphate sol...

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  12. What happens when baking soda is added to vinegar ? Write a word equat...

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  13. What happens when carbon dioxide gas is passed through lime water ? Wr...

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  14. When baking soda is mixed with lemon juice, bubbles are formed with th...

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  15. When a candle burns, both physical and chemical changes take place. Id...

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  16. Explain why, burning of wood and cutting of wood into small pieces are...

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  17. What happens when magnesium ribbon is burned in air ? Write a word equ...

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  18. What happens when magnesium oxide is dissolved in water ? Write a word...

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  19. Which one of the following is not a chemical change ?

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  20. Which of the following are physical changes? (i) Melting of iron met...

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