Exploring the Power of Hydrogen: Part 1
- Raman Ayan
- Feb 16, 2024
- 3 min read
Updated: Feb 21, 2024
Tick (✔) The correct choice amongest the following
1. The valency of hydrogen is :(a) 1(b) 2(c) 0(d) 3 |
2. The metals which can be used for producing hydrogen gas by reacting them with cold water are :(a) Na, Mg, Mn(b) Na, K, Ca(c) K, Al, Ca(d) K, Zn, Al |
3. The metals which can be used for producing hydrogen gas by reacting them with steam are :(a) Mg, Na, Zn(b) Mg, Zn, Fe(c) Mg, Cd, Sn(d) Zn, Sn, Cu |
4. The main component of natural gas is :(a) Methane(b) Hydrogen(c) Hydrogen and methane both(d) Nitrogen and oxygen only |
5. The metals which form ionic hydrides are :(a) Li, Na, Zn(b) Li, Na, Ca(c) Na, Cu, Al(d) Zn, Mg, Al |
Fill in The Blanks |
1. .................... named the gas hydrogen. |
2. Hydrogen was discovered by .................... in 1766. |
3. Hydrogen gas is prepared by the action of dil. H2SO4 on .................... . |
4. The melting point of hydrogen is .................... and boiling point is .................... . |
5. .................... zinc contains copper as impurity. |
Write True or False for each statment.Rewrite the Statement Correctly |
1. Hydrogen is a colourless, odourless and tasteless gas. |
2. Hydrogen is neither combustible nor a supporter of combustion. |
3. Hydrogen is absorbed by heated palladium. |
4. Hydrogen is heavier than air and readily soluble in water. |
5. Hydrogen is used for welding purposes in the form of oxy-hydrogen flame. |
Match The Columns |
| |
Give one Word for The Followings |
1. Flame used for welding purpose. |
2. Process used for manufacturing ammonia. |
3. Substance used to adsorb hydrogen. |
4. Colour of flame produced when hydrogen is burnt. |
5. Water turns anhydrous copper sulphate. |
6. Zinc used in laboratory preparation of hydrogen. |
7. Process in which carbon is converted to water gas. |
8. Method by which hydrogen gas is collected |
9. Process involves disinfection of water by using bleaching powder which releases chlorine and kills germs. |
10. The water which is free from any soluble and insoluble impurities, germs and bacteria ______ |
Answer The Followings Questions |
1. How is hydrogen prepared for its use in industries ? |
2. Write five uses of hydrogen. |
3. How is hydrogen prepared in the laboratory ? Explain with the help of a labelled diagram. |
4. What are ionic hydrides ? |
5. Hydrogen is the lightest gas. Explain with the help of an experiment. |
6. Write down an equation in which hydrogen reduces metal oxides to their respective metals. |
7. State three chemical properties of hydrogen. |
8. Write three physical properties of hydrogen. |
9. Write down the electronic configuration of hydrogen. |
10. Who discovered hydrogen ? |
11. Write down the symbol, atomic number and atomic mass of hydrogen. |
12. Name the metals which react with cold water to form hydrogen. |
13. Name the metals which react with acids. |
Answers
Tick (✔) The correct choice amongest the following 1. (a) 1 |
2. (b) Na, K, Ca |
3. (b) Mg, Zn, Fe |
4. (a) Methane |
5. (b) Li, Na, Ca |
Fill in The Blanks 1. Lavoisier |
2. Henry Cavendish |
3. granulated zinc |
4. 13.8 K, 20.4 K |
5. Granulated |
Write True or False for each statment.Rewrite the Statement Correctly 1. True |
2. False (Hydrogen is a combustible gas) |
3. True |
4. False (Hydrogen is lighter than air and insoluble in water) |
5. True |
Match The Columns 1. 1.Discovered hydrogen 2.Hydrogen 3.Welding 4.Named hydrogen |
Give one Word for The Followings 1. Oxy-hydrogen |
2. Haber's process |
3. Palladium |
4. Blue |
5. Blue |
6. Granulated zinc |
7. Bosch process |
8. Downward displacement of water |
9. Chlorination. |
10. Potable Water |
Answer The Followings Questions 1. Bosch process : In this method, red hot carbon is used to prepare hydrogen gas by the action of superheated steam.
 |
2. Uses of Hydrogen: 1. Oxy-hydrogen flame is used for welding purposes. 2. Mixture of helium and hydrogen is used for filling of balloons and airships. However, these days it is not used in airships because of its inflammable nature. 3. Hydrogen filled balloons along with meteorological instruments are sent up to record temperature, wind speed, air pressure, etc. 4. Mixture of liquid hydrogen and liquid oxygen is used as a rocket fuel. 5. Hydrogen is also used in the manufacture of vegetable ghee. Vegetable oil + H2 ----> Vegetable ghee |
3. In the laboratory, hydrogen gas is prepared by the action of dilute sulphuric acid on granulated zinc (see fig.). Granulated zinc is taken in a conical flask and dilute hydrochloric acid is poured through the thistle funnel.
 |
4. Metal hydrides where hydrogen exhibit a valency of - 1 are known as ionic hydrides. 2Li + H2 ----> 2LiH 2Na + H2 ----> 2NaH Ca + H2 ----> CaH2 |
5. Pass the hydrogen gas through a soap solution. The soap bubbles, containing hydrogen, rapidly rise up in the air. The bubbles produce a pop sound when they come in contact with burning matchstick. This activity shows that hydrogen is lighter than air and is an inflammable gas.
 |
6.  |
7. Three chemical properties of hydrogen are (i) It is combustible and burns with a blue flame to give water.  (ii) It acts as a reducing agent and reduces black CuO to reddish Brown copper.  (iii) It reacts with nitrogen to form ammonia in Haber's process.  |
8. (i) It is a colourless, odourless and tasteless gas. (ii) It is almost insoluble in water. (iii) It does not change the colour of either red or blue litmus solution. This shows that the gas is neither acidic nor basic, i.e., it is a neutral gas. |
9.  |
10. Henry Cavendish |
11. Symbol = H Atomic number = 1 Atomic mass = 1 |
12. K,Na,Ca |
13. Majority of metals react with acids |
HYDROGEN
EXERCISES
A. ANSWER THE FOLLOWING QUESTIONS IN ABOUT TWENTY WORDS.
Q. 1. Illustrate the reducing character of hydrogen by writing
a chemical equation.
Ans. Hydrogen can remove oxygen from any metal oxide and acts as
a reducing agent. The following chemical reaction illustrates the reducing
character of hydrogen.
heat
CuO(s) + H2
(g) → Cu(s) + H2
O(g)
Copper (II) oxide Hydrogen Copper Water
(Removal of oxygen)
Q. 2. Write one chemical equation for each to prepare
hydrogen from (a) water (b) acid.
Ans. (a) Hydrogen can be prepared by the action of active metals
on water. Different active metals displace hydrogen from water under
different conditions.
For example,
room temp.
Na(s) + H 2
O(l) → NaOH(aq) + H2
(g)
(vigorously)
Sodium Water Sodium hydroxide Hydrogen
(b) Hydrogen can be prepared by the action of acids o
metals : Acids contain replaceable hydrogen. Metals, such as, zinc,
magnesium etc., displace hydrogen from acids under room temperature
conditions.
For example,
room temp.
Zn(s) + dil. H 2
SO 4
(aq) → ZnSO4
(aq) + H2
(g) ↑
Zinc Sulphurric acid Zinc sulphate Hydrogen
Q.. How is hydrogen gas prepared in a laboratory ?
Describe with the help of a labelled diagram.
Ans. In laboratory, hydrogen gas is generally prepared by the
action of dilute H 2
SO4 on granulated zinc. The schematic diagram
of the process in shown below.
2 TEACHER’S MANUAL :: The World of Science–CHEMISTRY—8
Laboratory preparation of hydrogen gas
Zn(s) + H 2
SO 4
(aq) → ZnSO4
(aq) + H2
(g)
Zinc Sulphuric acid Zinc sulphate Hydrogen
Hydrogen gas obtained by the above reaction is collected through the
down displacement of water.
Q. 4. Write the chemical equations for the reaction of
hydrogen with (a) nitrogen (b) chlorine (c) sodium metal.
Ans. (a) Reaction of hydrogen with nitrogen gives ammonia.
Fe/Mo
N2
(g) + 3H2
(g) 2NH 3
(g) + Heat
200 atm, 450°C
Nitrogen Hydrogen Ammonia
(b) Hydrogen on eacting with chlorine gives hydrogen chloride.
diffused
H2
(g) → 2HCl(g)
sunlight
Hydrogen Hydrogen chloride
(c) Hydrogen eacts with sodium to form sodium hydride.
heat
2Na(s) → 2NaH(s)
Sodium
+ Cl2
(g)
Chlorine
+ H2
(g)
Hydrogen Sodium hydride
Q.. 5. Mention two uses of hydrogen.
Ans. The two uses of hydrogen are as follows :
(i) It is used as a fuel in rockets and guided missiles
(ii) It is used in welding
B.. TICK 4) THE CORRECT CHOICE.
1. Which of the following statements is incorrect ?
(a) hydrogen can fo m a positive ion by losing an electron.
(b) hydrogen can fo m a negative ion by gaining an electron.
(c) hydrogen can fo m coordinate bond with other elements.
(d) hydrogen can form covalent compounds with other elements.
2. The element which forms an ionic hydride with hydrogen is
(a) sodiu (b) xygen
(c) nitroge (d) carbo
3. The preparation of vanaspati ghee from vegetable oils involving
hydrogen in the presence of catalyst is called
(a) eduction
(c) hydrogenatio
(b) dehydrogenatio
(d) oxidation
4. Hydrogen does not reduce heated
(a) A 2
O 3 (b) CuO
(c) Sn 2 (d) Fe3
O 4
Ans. 1. (b) 2. (a) 3. (c) 4. (a)
C. FILL IN THE BLANK SPACES IN THE FOLLOWING STATEMENTS.
1. An atom of hydrogen contains one electron and one proton.
2. Water contains about 11% (by mass) of hydrogen.
3. Highly electropositive metal reacts with hydrogen to give
ionic hydrides.
4. The reduction of Ag2
O with hydrogen at higher temperature gives
silver and water.
5. Hydrogen is used as fuel in rockets.
HYDROGEN 3
D. WRITE T FOR TRUE AND F FOR ALSE STATEMENT.
1. Hydrogen occurs in abundance on the Sun.
2. Iron reacts with water at room temperature producing hydrogen
gas.
3. The reaction between hydrogen and chlorine takes place in the
presence of diffused sunlight.
4. Hydrogen can be used as a domestic fuel.
Ans. 1. True 2. False 3. True 4. False
E. MATCH THE TERMS/STATEMENTS IN COLUMN A WITH THOSE IN
COLUMN B.
Column A Column B
(i) ater
(ii) Reductio
1. The gas contained in bright stars
2. Source of hydrogen
3. Getting copper from copper (II) oxide (iii) Hydrogen
4. Reaction between H 2 and Cl 2 (iv) Photochemica
reaction
Ans. 1. (iii) 2. (i) 3. (ii) 4. (iv)
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