KSEEB SSLC Class 10 Science Solutions Chapter 4 Carbon and Its Compounds

KSEEB SSLC Class 10 Science Solutions Chapter 4 Carbon and Its Compounds are part of KSEEB SSLC Class 10 Science Solutions. Here we have given Karnataka SSLC Class 10 Science Solutions Chapter 4 Carbon and Its Compounds.

Karnataka SSLC Class 10 Science Solutions Chapter 4 Carbon and Its Compounds

KSEEB SSLC Class 10 Science Chapter 4 Intext Questions

Text Book Part II Page No. 5

Question 1.
What would be the electron dot structure of carbon dioxide which has the formula CO₂?
Answer:
In carbon dioxide molecule, the two oxygen atoms are bonded on either side with carbon atom be double bonds. These there are 2 double bonds in CO₂. Carbon shares its electrons in the formation of a double bond with one
oxygen atom and another two electrons with another oxygen atom. In this process, both the oxygen atoms and the carbon atom acquire the stable electronic configuration of the noble gas neon. The formation of CO₂ molecule is shown below.

Question 2.
What would be the electron dot structure of a molecule of sulphur which is made up of eight atoms of sulphur?
(Hint – The eight atoms of sulphur are joined together in the form of a ring.)
Answer:

Text Book Part II Page No. 12

Question 1.
How many structural isomers can you draw for pentane?
Answer:
Pentane has 3 structural isomers. We can write as follows.
i) CH₃-CH₂-CH₂-CH₂-CH₃

Question 2.
What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?
Answer:

1. Catenation: It is the ability to form bonds with other atoms of carbon.
2. Tetravalency: With the valency of four, carbon is capable of bonding with four other atoms.

Question 3.
What will be the formula and electron dot structure of cyclopentane?
Answer:
Molecular formula of cyclopentane is: C₅H₁₀
Electron dot structure:

Question 4.
Draw the structures for the following compounds.

1. Ethanoic acid
2. Bromopentane*
3. Butanone
4. Hexanal.

* Are structural isomers possible for bromopentane ?
Answer:

Question 5.
How would you name the following compounds?
(i) CH₃—CH₂—Br


Answer:

1. Bromoethane
2. Methanol
3. Hexane.

Text Book Part II Page No. 15

Question 1.
Why is the conversion of ethanol to ethanoic acid an oxidation reaction?
Answer:
Addition reaction means adding oxygen. Adding ethanol to potassium permanganate, we get ethanoic acid. Hence this reaction is called oxidation reaction.

Question 2.
A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?
Answer:
Air, also contains other gases like nitrogen, carbon dioxide and few more gases apart from oxygen. When ethyne is burnt in air, it gives a sooty flame. This is due to incomplete combustion caused by the limited supply of oxygen. However, if ethyne is burnt with oxygen, it gives a clean flame with temperature 3000°C because of complete combustion. This oxy-acetylene flame is used for welding. It is not possible to attain such a high temperature without mixing oxygen. This is the reason why a mixture of ethyne and air is not used,
2HC ≡ CH + 5O₂ → 4CO₂ + 2H₂O + Heat.

Text Book Part II Page No. 18

Question 1.
How would you distinguish experimentally between an alcohol and a carboxylic acid?
Answer:
All the carboxylic acids decompose sodium hydrogen carbonate giving brisk effervescence of carbon dioxide gas whereas ethanol does not react with sodium hydrogen carbonate

Experiment:

1. Take two test tubes, label them as A and B
2. Take about 0.5 g of sodium hydrogen carbonate (NaHco₃) in each test tube
3. Add 2 ml of ethanol in test tube A and 2ml of ethanoic acid in test tube B.
4. We can observe the gas bubbles in test tube B. No such bubbles are seen in test tube A. Pass the gas produced in test tube B through lime water taken in another test tube
5. We will find that lime water turns milky It is a test for carbon dioxide.

Hence, this experiment proves that when ethanoic acid reacts with sodium hydrogen carbonate, then carbon dioxide gas is produced with an effervescence (a rapid evolution of gas bubbles). Ethanol does not react with NaHCO₃.

Question 2.
What are oxidising agents?
Answer:
Oxidising agents are the substances that gain electrons in redox reaction and whose oxidation number is reduced. Examples: KMnO₄ or K₂Cr₂O₇. They have the ability to oxidize or give their oxygen to other substances.

Text Book Part II Page No. 20

Question 1.
Would you be able to check if water is hard by using a detergent?
Answer:
Detergent gives lather both with hard and soft water, while a soap gives lather with soft water only. Thus, it is not possible to check if the water is hard by using a detergent.

Question 2.
People use a variety of methods to wash clothes. Usually after adding the soap, they ‘beat’ the clothes on a stone, or beat it with a paddle, scrub with a brush or the mixture is agitated in a washing machine. Why is agitation necessary to get clean clothes?
Answer:
A soap molecule has two parts namely hydrophobic and hydrophilic. With the help of these particles, it attaches to the grease or dirt particle and forms a cluster called micelle. These micelles remain suspended as a colloid. To remove these micelles, it is necessary to agitate clothes.

KSEEB SSLC Class 10 Science Chapter 4 Textbook Exercises

Question 1.
Ethane, with the molecular formula C₂H₆ has
(a) 6 covalent bonds.
(b) 7 covalent bonds.
(c) 8 covalent bonds.
(d) 9 covalent bonds.
Answer:
(b) 7 covalent bonds.

Question 2.
Butanone is a four-carbon compound with the functional group
(a) carboxylic acid
(b) aldehyde
(c) ketone.
(d) alcohol.
Answer:
(c) ketone.

Question 3.
While cooking, if the bottom of the vessel is getting blackened on the outside, it means that
(a) the food is not cooked completely.
(b) the fuel is not burning completely.
(c) the fuel is wet.
(d) the fuel is burning completely.
Answer:
(b) the fuel is not burning completely.

Question 4.
Explain the nature of the covalent bond using the bond formation in CH3Cl.
Answer:
Carbon has a valency of four. It shares one electron to each 3 hydrogen atoms and one more electron with chlorine.

Question 5.
Draw the electron dot structures for
(a) ethanoic acid.
(b) H₂S.
(c) propanone.
(d) F₂.
Answer:
a) Ethanoic acid

b) H₂S

c) propanone

(d) F₂

Question 6.
What is an homologous series? Explain with an example.
Answer:

A homologous series is a series of carbon compounds that have different numbers of carbon atoms but contain the same functional group. Every next member of a homologous series has a clear difference of 14 units of mass.

For example, methane, ethane, propane, etc., are all part of the alkane homologous series. The general formula of this series is C_nH_2n+2.

An example is explained with formula as below:

1. Methane, CH₄
2. Ethane, CH₃CH₃
3. Propane, CH₃CH₂CH₃
4. Butane, CH₃CH₂CH₂CH₃

It can be noticed that there is a difference of -CH₂ unit between each successive compound.

Question 7.
How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties?
Answer:

Ethanol and Ethanoic acid can be differentiated on the basis of their following properties by:

1. Ethanol is a liquid at room temperature with a pleasant smell. Ethanoic acid has a melting point of 17°C. Since it is below the room temperature so, it freezes during winter. Moreover, ethanoic acid has a smell like vinegar.
2. Ethanol does not react with metal carbonates while, ethanoic acid reacts with metal carbonates to form a salt, water and carbon dioxide.
   For example:
   2CH₃COOH + Na₂CO₃ → 2CH₃COONa + CO₂ +H₂O
3. Ethanol does not react with NaOH while ethanoic acid reacts with NaOH to form sodium ethanoate and water.
   For example,
   CH₃COOH + NaOH → CH₃COONa + H₂O
4. Ethanol is oxidized to give ethanoic acid in the presence of acidified KMnO₄ while no reaction takes place with ethanoic acid in the presence of acidified KMnO₄.

Difference in physical properties:

Ethanol	Ethanoic acid
This is in liquid form at room temperature. Its melting point is 156° K.	Its melting point is 290K and hence it often freezes during winter in cold climates.
Difference in chemical properties
Ethanol will not react with metallic carbo­nates.	Ethanoic acid reacts with carbo­nates and Hydrogen carbonate and forms salts, carbon dioxide and water.

Question 8.
Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents such as ethanol also?
Answer:
A soap molecule has two ends. One end is hydrophilic and another end is hydrophobic. When soap is dissolved in water and clothes are put in the soapy solution, soap molecules converge in a typical manner to make a structure is called micelle. The hydrophobic ends of different molecules surround a particle of grease and make the micelle, which is a spherical structure.

In this, the hydrophilic end is outside the sphere and hydrophobic end is towards the centre of the sphere. This is why micelle formation takes place when soap is added to water. Since ethanol is not as polar as soap, micelles will not be formed in other solvents such as ethanol.

Question 9.
Why are carbon and its compounds used as fuels for most applications?
Answer:
Carbon in all its allotropic forms, burns in oxygen to give carbondioxide along with the release of heat and light. Most carbon compounds also release a large amount of heat and light on burning. Hence carbon and its compounds are used as fuels for most applications.

Question 10.
Explain the formation of scum when hard water is treated with soap.
Answer:
Hard water often contains salts of calcium and magnesium. Soap molecules react with the salts of calcium and magnesium and form a precipitate. This precipitate begins floating as an off-white layer over water. This layer is called scum. Soaps lose their cleansing property in hard water because of the formation of scum.

Question 11.
What change will you observe if you test soap with litmus paper (red and blue)?
Answer:
Soap is basic in nature, hence red litmus changes to blue. Blue litmus is seen blue only.

Question 12.
What is hydrogenation? What is its industrial application?
Answer:

Hydrogenation is a reaction between hydrogen and other compounds in the presence of the desired catalyst. Hydrogenation is used for reducing saturated hydrocarbons. Hydrogenation is an addition reaction. For example: When ethane is heated with the catalyst, nickel, it is reduced to ethane.

Industrial application:

1. In the petrochemical industry, hydrogenation is used to convert alkenes into alkanes (paraffin) and cyclo-alkanes.
2. It is also used to prepare vegetable cooking fat from vegetable oils.

Question 13.
Which of the following hydro-carbons undergo addition reactions:
C₂H₆, C₃H₈, C₃H₆, C₂H₂ and CH₄.
Answer:
C₂H₆ and C₂H₂ are unsaturated Hydrocarbons. Hence these undergo addition reactions.

Question 14.
Give a test that can be used to differentiate between saturated and unsaturated hydrocarbons.
Answer:
Butter contains saturated fats. Therefore, it cannot be hydrogenated. On the other hand, oil has unsaturated fats. That is why it can be hydrogenated to saturated fats (solids).

Question 15.
Explain the mechanism of the cleaning action of soaps.
Answer:

Soap are molecules in which the two ends have differing properties. One is hydrophilic, that is, it interacts with water, while the other end is hydrophobic, that is, it interacts with hydrocarbons. In the clusters of molecules in which the hydrophobic tails are on the surface of the cluster. This formation is called micelle.

Since the oily dirt will be collected in the centre of the micelle. The micelles stay in solution as a colloid and will not come together to precipitate because of ion-ion repulsion. Thus the dirt suspended in the micelles is also easily rinsed away.

KSEEB SSLC Class 10 Science Chapter 4 Additional Questions and Answers

Question 1.
Write the electron dot formula of O₂.
Answer:

Question 2.
What is substitution Reaction? Give an example.
Answer:
If one type of atom or a group of atoms takes the place of another, it is called substitution reaction.
Eg: CH₄ + Cl₂ CH₃Cl + HCl (in the presence of sunlight)

Question 3.
Name 2 commercially important compounds.
Answer:
Ethanol and ethanoic acid.

Question 4.
Give an example for Esterification reaction.
Answer:

Question 5.
Write one use of ester.
Answer:
Esters are used in making perfumes and as flourishing agents.

Question 6.
What are detergents?
Answer:
Detergents are generally sodium salts of sulphonic acids or ammonium salts with chlorides or bromides etc.

Question 7.
Where is Ethanol used?
Answer:
It is used in medicines such as tincture iodine, cough syrups, and many tonics.

Question 8.
What is vinegar? Mention one of its use.
Answer:
5 to 8% solution of acetic acid in water is called vinegar. It is used as a preservative in pickles. We hope the given KSEEB SSLC Class 10 Science Solutions Chapter 4 Carbon and Its Compounds will help you. If you have any query regarding Karnataka SSLC Class 10 Science Solutions Chapter 4 Carbon and Its Compounds, drop a comment below and we will get back to you at the earliest.