Kerala Syllabus 9th Standard Chemistry Solutions Chapter 6 Non-Metals
Kerala Syllabus 9th Standard Chemistry Solutions Chapter 6 Non-Metals
Kerala State Syllabus 9th Standard Chemistry Solutions Chapter 6 Non-Metals
Non-Metals Textual Questions and Answers
Activities In The Text
9th Class Chemistry Chapter 6 Solutions Kerala Syllabus Question 1.
Which are the non-metals familiar to you?
Answer:
Nitrogen, Oxygen, Chlorine, Argon
Class 9 Chemistry Chapter 6 Notes Kerala Syllabus Question 2.
Is it interesting to see the balloons flying up in the air? Which is the gas-filled in these balloons?
Answer:
Hydrogen.
Kerala Syllabus 9th Standard Chemistry Chapter 6 Question 3.
Which gas is mainly filled in cylinders used in hospitals for artificial respiration?
Answer:
Oxygen
Kerala Syllabus 9th Standard Chemistry Notes Question 4.
Which is the gas-filled in tires to increase their efficiency?
Answer:
Nitrogen
9th Chemistry Kerala Syllabus Question 5.
Which are the gases present in air
| Components | Percentage |
| Nitrogen | 78.08 |
| Oxygen | 20.95 |
| Argon | 0.9 |
| Carbon dioxide | 0.038 |
| Other | 0.032 |
Which is the most abundant gas in air?
Answer:
Nitrogen
Chemistry 9th Class Notes Kerala Syllabus Question 6.
Write the constituent elements of food materials?
Answer:
Carbohydrates: carbon, hydrogen, oxygen
Protein: carbon, hydrogen, oxygen, nitrogen
Fat: carbon, hydrogen, oxygen
9th Chemistry Notes Kerala Syllabus Question 7.
List the constituent elements of some plastics?
Answer:
PVC: Carbon, hydrogen, chlorine Polythene: Carbon, hydrogen Carbon, hydrogen, oxygen, nitrogen, chlorine are nonmetals
Chemistry Class 9 Chapter 6 Kerala Syllabus Question 8.
What do you know about hydrogen gas?
Answer:
Hydrogen is the major component in the sun and stars. A very small quantity of hydrogen is seen in the atmosphere in free state. Water is a major com¬pound of hydrogen. Hydrogen is present in large amounts in bio substances.
9 Chemistry Kerala Syllabus Question 9.
List out the hydrogen compounds known to you
Answer:
1. H2SO4 HCI HNO3 H2CO3
2. H2O H2O2 NaOH H2PO4
9 Chemistry Kerala Syllabus Question 10.
Explain the preparation of hydrogen in the laboratory?
Materials required: Test tube, zinc granule, dilute hydrochloric acid, lighted match stick.
Procedure: Take 5 ml. dilute hydrochloric acid in a test tube and add some zinc granule to it. Bring a burning match stick at the mouth of the test tube. What do you observe?
Answer:
The gas burns with a pop sound
Class 9 Chemistry Notes Kerala Syllabus Question 11.
Which gas is produced?
Answer:
Hydrogen.
Chemistry Notes Class 9 Kerala Syllabus Question 12.
Write the balanced equation of this chemical reaction.
Answer:
Zn + 2HCl → ZnCl2 + H2
Chemistry 9th Kerala Syllabus Question 13.
What are the reactants and products in this reaction?
Answer:
Zn, HCl – Reactants ZnCl2 + H2 – Products
Kerala Syllabus 9th Standard Chemistry Solutions Question 14.
How is zinc chloride formed along with hydrogen gas in this chemical reaction?
Answer:
During this chemical reaction, Zn atom replaces hydrogen in hydrochloric acid.
Chemistry Class 9 Notes Kerala Syllabus Question 15.
What are displacement reactions?
Answer:
Reactions, where an element in a compound is displaced by another element, is called displacement reactions/ Substitution reactions.
9 Standard Chemistry Kerala Syllabus Question 16.
Give examples for displacement reactions.
Answer:
1) Mg + 2HCl → MgCl2 + H2
2) Zn + H2SO4 → ZnSO4 + H2
3) Mg + 2HNO3 → Mg(NO3 )3 + H2
4) Zn + CuSO4 → ZnSO4 + Cu
5) 2NaBr + Cl2 → 2NaCl + Br2
6) CH4 + Cl2 → CH3Cl + HCl
Question 17.
You have seen hydrogen balloons fly up in the air. What can you infer about the density of hydrogen from this?
Answer:
The density of hydrogen is less than that of air.
Question 18.
What is the reaction between hydrogen and oxygen?
Answer:
Hydrogen burns in oxygen to form water. This is an exothermic reaction. (Water is also formed when electric sparks are passed through a mixture of hydrogen and oxygen)
2H2 + O2 → 2H2O + heat
Question 19.
What is a combination reaction?
Answer:
The reaction in which two or more simple substances (elements/compounds) combine to form a compound is called combination reaction.
eg: 2H2 + O2 → 2H2O
Question 20.
What is the reaction between hydrogen and chlorine?
Answer:
Hydrogen combines with chlorine in the presence of sunlight to form hydrogen chloride
Question 21.
Give examples for combination reactions.
1) N2 +3H2 → 2NH3
2) 2Mg + O2 → 2MgO
3) H2 + S → H2S
4) 2Na + H2 → 2NaH
5) CaO + H2O→ Ca(OH)2
Qn. 22
List the uses of hydrogen
Answer:
- For the industrial production of ammonia and methanol
- To saturate unsaturated oils
- As a fuel
Question 23.
Observe and analyse the graph showing the heat energy released during the combustion of various fuels.
Which among the fuels given has the highest calorific value?
Answer:
Hydrogen
Question 24.
What is calorific value?
Answer:
The calorific value of a fuel is the heat energy released from one unit mass of that fuel on complete combustion.
Question 25.
Which fuel has the highest calorific value?
Answer:
Hydrogen
Question 26.
What will be the product formed when hydrogen burns in air?
Answer:
Water(H20)
Question 27.
What are the advantages of using hydrogen as a fuel?
Answer:
- High calorific value
- No environmental pollution
- Availability is very high
Question 28.
What are the limitations of using hydrogen as a fuel?
Answer:
- Hydrogen is a gas that burns explosively in air
- Distribution and storing the gas is not easy.
Question 29.
List out some compounds containing oxygen.
Answer:
- C6H12O6
- CuO
- CaCO3
- H2SO4
Question 30.
Prepare and present a short note on the role of plants in maintaining the oxygen level.
Answer:
In the presence of sunlight, the chlorophyll present in plants forms glucose by combining CO2 and water. As a result of this reaction (photosynthesis), oxygen is liberated. This helps to maintain the oxygen level in the atmosphere.
6CO2 + 6H2O → C6H12O6 + 6O2
Question 31.
What do know about the presence of oxygen on earth
Answer:
| Earth crust | 45-50% |
| Water | 88-90% |
| Air | 21% |
| Plants | 60-70% |
| Animals | 60-70% |
From the table you might have understood that the level of oxygen is very high in nature
Question 32.
Explain the preparation of oxygen in the laboratory with a figure?
Question 33.
Write the apparatus materials used for the preparation of oxygen?
Answer:
- Dry boiling tube
- Crystal of potassium permanganate
- Spirit lamp
- Glowing splinter
Question 34.
Introduce a glowing matchstick into the boiling tube. What do you observe?
Answer:
The glowing matchstick flares up.
Question 35.
Presence of which gas is indicated by the flaring up of the glowing matchstick?
Answer:
oxygen
Question 36.
Complete the equation of this chemical reaction.
Answer:
Question 37.
What is decomposition?
Answer:
Decomposition is the process of forming two or more products due to the decomposition of a compound.
Question 38.
What happens during the electrolysis of water? Com¬plete its chemical equation given below
Answer:
Question 39.
Put a (✓) mark against the correct option related to oxygen from those given below.
Answer:
Colour — Yes/ No ✓
Odour — Yes/ No ✓
Solubility in Water — Soluble✓/insoluble
Density — More than air ✓/less than air
Flammability — supports combustion✓
Question 40.
What is combustion?
Answer:
The burning of a substance in oxygen is called combustion.
Question 41.
Take some sulphur in a spatula and burn it. What do you observe?
Answer:
Sulphur burns. The smell of gun powder.
Question 42.
How does oxygen react with non-metals?
Answer:
Oxygen reacts with the non-metals such as carbon and hydrogen to produce carbon dioxide and water respectively,
e.g: C + O2 → CO2.
2H2 + O2 → 2H2O
Question 43.
Have you notice that the lustre of metals like aluminium and ion fades gradually. Give reason?
Answer:
The reason for this is the formation of oxide of these metals when they combine with oxygen
Question 44.
Explain the uses of oxygen
Answer:
- For combustion
- As an oxidant in rocket fuels
- For artificial respiration
Question 45.
What is ozone?
Answer:
Oxygen is seen as diatomic molecule that is formed by combining two oxygen atoms.
But ozone is a triatomic molecule containing three oxygen atoms. (03)
Ozone is found in the stratosphere, a layer of atmosphere.
Question 46.
How ozone is formed in the atmosphere?
Ozone is present mostly in the stratosphere of the atmosphere. Atmosphere oxygen dissociates on absorption of high energy ultraviolet radiation. The oxygen atoms thus formed combine together to form 03 molecule.
Question 47.
Depletion of ozone in the atmosphere reduces the absorption of ultraviolet rays. Justify the statements.
Answer:
Chloroflouro carbons are responsible for the depletion of the ozone layer. Chlorofluorocarbon released into the atmosphere reach the stratosphere and breakdown by the action of ultraviolet radiation releasing chlorine the chlorine decomposes ozone molecules into oxygen. This disturbs the equilibrium in the ozone – oxygen cyclic process. Hence the depletion of ozone in the atmosphere reduces the absorption of ultraviolet rays.
Question 48.
Howto reducing the rate of depletion of ozone layer?
Answer:
Today the use of CFC is being controlled in most of the countries. Harmful CFC are replaced nowadays with safer substances this has helped in reducing the rate of depletion of ozone layer.
Question 49.
Nitrogen is the chief constituent of atmospheric air have you ever thought of the advantage of having a greater quantity of nitrogen in the atmosphere?
Answer:
Nitrogen molecule has a triple bond (N = N). Because of this strong bond, nitrogen is most inert oxygen helps in combustion while nitrogen plays on important role in regulating the rate of combustion of oxygen.
Question 50.
What are the different ways in which nitrogen is obtained by plants?
Answer:
- By bio decomposition
- Through fertilizers
- By nitrogen-fixing by bacteria
Question 51.
“It is said that lightning is a boom to plants”. Justify the statement?
Answer:
During lightening the triple bond in nitrogen breaks and combine with the atmospheric oxygen to form nitric oxide (NO)
N2+O2 → 2NO
Nitric oxide thus formed further combines with more amount of oxygen to form nitrogen dioxide (NO2)
2NO + O2 → 2NO2
Nitrogen dioxide dissolves in rainwater in the presence of oxygen and reaches the soil as nitric acid (HNO3)
4NO2 + 2H2O + O2 → 4HNO3
Nitric acid reacts with the minerals in the soil to form nitrate salts which is absorbed by the plants. So it is said that lightning is a boom to plants.
Question 52.
Can you list out which other means are there for getting greater amount of elements for plants?
Answer:
- Use of organic fertilizers
- Use chemical fertilizers
- Bio decomposition
- Through nitrogen fixation
Question 53.
List the merits and limitations of the application of organic fertilizers?
Answer:
Merits:
- Eco-friendly
- Preserve the inmate nature of the soil
Limitation:
- Biodegradation needs time so it cannot easy to absorbed by plants in time.
- Presence of microorganism is necessary.
- Storage and transportation not easy.
Question 54.
What are the other uses of nitrogen?
Answer:
- In production of nitrogenous fertilizers
- To fill in the tyres of vehicles
- Liquified nitrogen as a refrigerant
- Tc avoid the presence of oxygen in packed foods
- In the manufacture of ammonia
Question 55.
List out the chlorine compounds you are familiar with.
Answer:
- Hydrogen chloride (HCl)
- Sodium chloride (NaCl)
- Potassium chloride (KCl)
Question 56.
Draw the arrangement for the preparation of chlorine in the laboratory.
Answer:
Question 57.
Write the balanced chemical equation?
Answer:
2KMnO4 +16HCl → 2KCl + 2MnCl2 + 8H2O + 5Cl2
Question 58.
What are the reactants required for the preparation of chlorine?
Answer:
Potassium permanganate, Con. HCI
Question 59.
What are the products obtained?
Answer:
Potassium chloride (KCl)
Manganous chloride (MnCl2)
Water (H2O)
Chlorine (Cl2)
Question 60.
In laboratory preparation of chlorine why chlorine gas is passed through water?
Answer:
Hydrogen chloride vapours conning along with chlorine is removed by passing it through water.
Question 61.
Which method is used to remove the water vapour formed along with chlorine?
Answer:
The chlorine gas formed can be passed through con. H2SO4 because it can absorb the water vapour formed along with chlorine.
Question 62.
Observe the figure and see the way in which chlorine is being collected in a gas jar? Why this method is used?
Answer:
The density of Cl2 is greater than that of air hence it can be collected by the upward displacement of air.
Question 63.
Explain the physical properties of chlorine?
Colour – colourless
Odour – pungent smell
Density -greater than that of air
Question 64.
Describe an experiment to show the bleaching action of chlorine?
Answer:
Prepare and store dry chlorine in a gas jar. Put some moist petals of colour flowers and pieces of coloured paper in the jar. The observation is chlorine gas can decolourise coloured substances by bleaching.
Question 65.
Write the chemistry behind the bleaching action of chlorine?
Answer:
Chlorine gas reacts with the water to give hydrochloric acid hypochlorous acid (HClO)
Cl2 + H2O → HCl + HOCl
Hypochlorous acid decomposes and liberate atomic oxygen.
HClO → HCl + [O]
This atomic oxygen oxidises coloured substances.
Question 66.
Write the uses of chlorine?
Answer:
- For bleaching
- For the preparation of insecticides
- For removing stains in the fabric
- For purification of water
- For the preparation of bleaching powder
Question 67.
How bleaching powder is prepared?
Answer:
Bleaching powder is prepared by passing dry chlorine gas over dry slaked lime.
Question 68.
How bleaching powder act as a disinfectant?
Answer:
Chlorine, liberated when bleaching powder reacts with water, helps disinfection. Bleaching powder is a good source of chlorine.
Question 69.
How the presence of a chloride salt can be confirmed?
Answer:
When silver nitrate solution is added to the given salt solution, if a white curdy precipitate soluble in ammonium hydroxide solution, is formed the pres¬ence of a chloride salt can be confirmed.
NaCl + AgNO3 → AgCl + NaNO3
Question 70.
Analyse the chemical equation given below.
NaCl + AgNO3 → AgCl + NaNO3
Which is the ion combined with sodium ion in the
first reactant NaCl?
Answer:
Cl–
Question 71.
To which metal ion, is this ion combined in the product?
Answer:
Ag+
Question 72.
To which metal ion is this nitrate ion combined now in the product.
Answer:
Na+
Question 73.
Are the ions interchanged here?
Answer:
Yes
Question 74.
What is double decomposition reaction?
Answer:
Double decomposition is a reaction in which two compounds when react with each other, interchange their ions to form two new compounds.
eg: 1) NaCl + AgNO3 → AgCl + NaNO3
2) H2SO4+BaCl2 → 2HCl + BaSO4
Question 75.
Arrange the chemical reactions given below in the table under the heads combination reaction, decom¬position, displacement reactions and double decomposition.
a) 2KCl → 2K + Cl2
b) CaCO3 → CaO + CO2
c) 2Hl → H2+l2
d) KCl + AgNO3 → AgCl + KNO3
e) Mg + 2HCl → MgCl2 + H2
f) 2H2 + O2 → 2H2O
g) Mg + H2SO4 → MgSO4 + H2
h) Na2SO4 + BaCl2 → BaSO4 + 2NaCl
Answer:
a) Decomposition
b) Decomposition
c) Combination
d) Double decomposition
e) Displacement
f) Combination
g) Displacement
h) Double decomposition
Let’S Assess
Question 1.
Some chemicals are given in the box. Find out and write down the chemicals needed to prepare oxygen and hydrogen in laboratory.
Sulphuric acid, hydrochloric acid, sodium nitrate, zinc, potassium permanganate, ammonium chloride, water.
Answer:
Oxygen — Potassium permanganate
Hydrogen — Zinc, Hydrochloric acid
Question 2.
Find out to which gases are the following statements related?
a) The gas which is combustible and is formed through the electrolysis of water
b) The gas that is used for water purification.
c) The element inevitable for the growth of plants.
d) The gas formed by the thermal decomposition of KMnO.
Answer:
a) Hydrogen
b) Chlorine
c) Nitrogen
d) Oxygen
Question 3.
Certain nonmetals and their uses are given in the wrong order in the table below. Match them correctly.
Element — Uses
Hydrogen — Disinfectant
Oxygen — Refrigerant
Chlorine — Fuel
Nitrogen — Biodegradati
Answer:
Element — Uses
Hydrogen — Fuel
Oxygen — Biodegradati
Chlorine — Disinfectant
Nitrogen — Refrigerant
Question 4.
a) What are the chemicals used for the preparation of chlorine in the laboratory?
b) why is chlorine passed through sulphuric acid during its preparation?
c) how will you prepare bleaching powder?
d) Name the gas that comes out of bleaching powder in the presence of water?
Answer:
a) Potassium permanganate concentrated HCl
b) It can absorb water vapour in the chlorine gas obtained
c) Bleaching p[owder is prepared by passing dry chlorine over dry slaked lime.
Question 5.
“We should give up chemical fertilizers completely and promote the use of organic fertilizers”. Do you agree with this statement? Substantiate your answer.
Answer:
Yes
- Organic fertilizers are echofriendly.
- Preserve the inmate nature of the soil.
- Does not create any health problem.
Question 6.
Classify the given chemical reactions in the table below.
a) Mg + O2 → 2MgO
b) H2 + l2 → 2HI
c) 2H2O → 2H2 + O2
d) NaCl + AgNO3 → AgCl + NaNO3
e) ZnSO4 + BaCl2 → BaSO4 + ZnCl2
f) Zn + H2SO4 → ZnSO4 + H2
g) FeSO4 + Zn → ZnSO4 + Fe
h) CaCO3 → CaO + CO2
Answer:
a) Combination
b) Combination
c) Decomposition
d) Double decomposition
e) Double decomposition
f) Displacement
g) Displacement
Extended Activities
Question 1.
Conduct a discussion on how nitrogen cycle benefits plants and animals.
Answer:
Nitrogen cycle helps to maintain the level of nitrogen in the atmosphere stable. During lightning nitro¬gen in the atmosphere combines with oxygen and forms nitric oxide. This nitric oxide combines with oxygen again to form nitrogen dioxide Nitrogen dioxide in the presence of oxygen dissolves in rainwater and reaches earth as nitric acid. This nitric acid combines with compounds present in earth and changes them to nitrates. Plants absorb this nitrates easily. Through plant products, nitrogen reacts animals also When plants and animals decay nitrogen again reaches the atmosphere this process goes on continuously. So the amount of nitrogen is kept constant.
Question 2.
Conduct a seminar on ‘Ozone Depletion and its Solutions’
Answer;
Ozone is present mostly in the stratosphere of the atmosphere. Atmosphere oxygen dissociates on absorption of high energy ultraviolet radiation. The oxy¬gen atoms thus formed combine together to form 03 molecule.
Ozone absorbs low energy ultraviolet radiations and decomposes back to oxygen as a result of this cyclic process the level of ozone remains constant. In the atmosphere.
The energy required for this process is obtained from the ultraviolet process is obtained form the ultraviolet radiations emitted by the sun. Due to this such harmful radiations doe not reach the earth excessively.
Chloroflouro carbons are responsible for the depletion of the ozone layer. Chlorofluorocarbon released into the atmosphere reach the stratosphere and breakdown by the action of ultraviolet radiation releasing chlorine the chlorine decomposes ozone molecules into oxygen. This disturbs the equilibrium in the ozone – oxygen cyclic process. Hence the depletion of ozone in the atmosphere reduces the absorption of ultraviolet rays.
Today the use of CFC is being controlled in most of the countries. Harmful CFC are replaced nowadays with safer substances this has helped in reducing the rate of depiction of ozone layer.
Question 3.
Take 5 ml hydrogen peroxide (H202) solution in a test tube. Add a little manganese dioxide to it. Bring a burning matchstick into the test tube. What do you observe? Find reason for your observation?
Answer:
Observation: The burning matchstick flares up. Reason: In the presence of manganese dioxide, hydrogen peroxide decomposes quickly and liberates oxygen gas. The presence of oxygen flaring up of the match stick.
2H2O2 → 2H2O + O2
Non-Metals More Questions and Answers
Question 1.
Certain gases are given below Hydrogen oxygen-nitrogen chlorine, carbon dioxide
a) Which is a combustible gas?
b) Which gas support combustion?
c) Which gas has the tendency to limit combustion?
d) Which gas resist combustion?
Answer:
a) Hydrogen
b) Oxygen
c) Nitrogen
d) Carbondioxide
Question 2.
Classify the following gases into molecules having single bond, double bond and triple bond
a) Nitrogen
b) Chlorine
c) oxygen
Answer:
Single bond – Chlorine
double bond – Oxygen
Triple Bond-Nitrogen
Question 3.
Which one of the following doesn’t belong to the group?
Carbohydrates, protein, polythene, Fats
Answer;
Polythene
Question 4.
The components in food materials are given below. Filling the missing ones
a) Carbohydrate – Carbon, Hydrogen, …………
b) Protein – Carbon, Hydrogen, Oxygen,
c) Fats – Carbon, Hydrogen,
Answer:
a) Oxygen
b) Nitrogen
c) Nitrogen
Question 5.
Identify the relation in the first pair and fill up the missing ones in the second pair
a) PVC: Carbon, Hydrogen, Chlorine
…………..: Carbon, Hydrogen
b) Aqueous solution of CO2: H2CO3
Aqueous solution of SO2:
c) Na2CO3.10.H2O : Washing soda
NaHCO3 :…….
Answer;
a) Polythene
b) H2SO3
c) Baking soda
Question 6.
Certain gases are given in column A. Chemicals required to produce the gases are given in column B. Match them suitably.
| A | B |
| Hydrogen | Calciumcarbonate + dil. HCl |
| Oxygen | Potassium permanganate |
| Chlorine | Magnessium + dil HCl |
| Carbondioxide | Potassium permanganate + Conc.HCl |
Answer:
| A | B |
| Hydrogen | – Magnesium + dil. HCl. |
| Oxygen | – Potassium permanganate |
| Chlorine | – Potassium permanganate + cone. HCl |
| Carbon dioxide | – Calcium carbonate + dil. HCl |
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