Page 147 - ICSE Chemistry 8

You will see that the solu on becomes colourless.
The stage when the base is completely neutralised by the acid is the neutralisa on point, i.e., when the
solu on becomes completely pink.

C. Answer in detail.

1. Write the characteris cs of chemical reac ons.
2. With the help of an ac vity, show the forma on of a precipitate during a chemical reac on.
3. Discuss the condi ons that are necessary for chemical reac ons to take place.

4. Write a note on types of chemical reac ons.
5. With the help of an ac vity, discuss the thermal decomposi on of ammonium chloride.

6. How is a precipita on reac on diff erent from a neutralisa on reac on?
7. Write a note on redox reac on explaining oxida on, reduc on, oxidising agent and reducing agent
with examples.
8. Discuss the forma on of acidic oxides and basic oxides.

OBSERVE AND PERFORM

Observe the given image carefully and answer the following ques ons.

conical fl ask

dilute
sulphuric hydrogen gas
acid bubbles
zinc granules

1. What does the image represent?
2. What happens on adding the dilute sulphuric acid over zinc granules?

APPLY YOUR LEARNING LIFE SKILLS

A. When substance X is heated, carbon dioxide gas is Iden fy the chemical reac ons that
evolved. If this gas is passed through lime water, lime take place in our daily lives. Discuss the
water turns milky. Name the substance X. importance of these chemical reac ons in
B. When hydrogen sulphide gas is passed through blue- our lives. On the basis of your observa ons,
coloured copper sulphate solu on, a solid substance create a PowerPoint presenta on on the
is formed. What is this substance called? Name the topic ‘Chemical Reac ons in Everyday Life’.
solid substance formed in this reac on.
(Cri cal-thinking, Observa on, Interpreta-
C. Enzyme X present in the living cells of yeast helps
on and Analysis)
in the fermenta on of glucose in alcohol. Name the
enzyme.

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