Page 167 - ICSE Chemistry 8

Review Your Learning

A. Fill in the blanks.
1. Hydrogen makes up almost ____________ of the ma er in the universe.

2. ______________ discovered the element hydrogen in 1766.
3. Sodium when treated with cold water liberates ____________ and forms ____________.
4. _____________ is made by adding a few drops of dilute sulphuric acid to make it a be er conductor
of electricity.
5. The mel ng point of hydrogen is __________ and its boiling point is _____________.

6. Hydrogen gas liquefi es into a colourless liquid at ____________ and ___________ atmospheric
pressure.

B. State whether the given statements are true (T) or false (F).

1. An atom of hydrogen consists of two protons around which one electron revolves
2. Metals below hydrogen in the ac vity series displace hydrogen from water and dilute acids.
3. Dilute nitric acid liberates hydrogen in the ac vity series of metals.
4. Hydrogen gas is collected by the downward displacement of water.

5. The reac on of hydrogen with oxygen is highly endothermic.
6. Hydrogen gas is a highly infl ammable gas and burns with a pop sound.

C. Match the columns.
Column A Column B
1. Displacement reac on (a) Ac vity series of metals

2. Electrolysis (b) Water gas
3. Bosch’s process (c) Haber’s process
4. Oxida on (d) Reduc on
5. Redox reac on (e) Cataly c hydrogena on of oils

D. Answer the following ques ons.
1. Write a note on the discovery of hydrogen.
2. What are displacement reac ons?
3. How can hydrogen be prepared by electrolysis of water?

4. Discuss the laboratory prepara on of hydrogen.
5. What are the physical and chemical proper es of hydrogen?
6. How can you test the presence of hydrogen?
7. Write a note on oxida on and reduc on reac ons.
8. Write the uses of hydrogen.

PROJECT
Create a PowerPoint presenta on on the topic ‘How to Reduce Air Pollu on’. Find the related informa on
and images using the Internet. Add related videos in the presenta on. Format it as per your choice.

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