This worksheet 28 contains questions based on Chapter 28 Carbon and its Compounds of NIOS Class 10 Science and Technology (212) along with complete and accurate answers.
This post explains the answers of questions given in the worksheet including
explanation, diagrams. These solutions will help you complete your assignments and TMA also.
Carbon and its Compounds Worksheet 28 Solution
Q1.Name the element whose one of the allotropic forms is buckminsterfullerene.
Answer
Carbon is the element whose one of the allotropic forms is bickminsterfullerence.
Q2. In addition to some propane and ethane, LPG cylinders contain mainly two isomers of another alkane. Name the two isomers and write their condensed structural formulae.
Answer
In LPG cylinders along with small amounts of propane and ethane, the main
component is butane which exists in two isomeric forms.
The two isomers of butane are:
i. n- Butane (Normal butane)
ii. isobutane (2-methylpropane)
Condensed Structural Formula of isomers of butane
(i) CH3-CH2-CH2 -CH3
(ii) CH3-CH -CH3
|
CH3
Q3.Name the black substance of pencil. Will the current flow through the electrical circuit when we use the sharpened ends of the pencil to complete the circuit?
Answer
The black substance used in pencil is Graphite which is an allotrope of carbon.
Yes, electric current will flow through the circuit when the sharpened ends of the
pencil are used to complete the circuit because graphite is a good conductor of
electricity.
Q4. How does graphite act as a lubricant?
Answer
Graphite acts as a lubricant because its structure is made of layers of carbon atoms
arranged in hexagonal rings. The forces between these layers are very weak so
the layers can slide easily over one another.
So, due to this sliding property, graphite reduces friction between surfaces and
therefore it is used as a lubricant (dry lubricant).
Q5. Write the electron dot structure for : (i) ethane (ii) ethene (iii) ethyne.
Answer
Q6. Give the IUPAC name of the following compound: C2H6
Answer
Ethane
Q7.Write the name of any two isomers represented by the molecular formula C5H12.
Answer
(i) n-Pentane
(ii) Iso pentane (2-methyl butane)
Q8. A neutral organic compound is warmed with some ethanoic acid and a little of conc. H2SO4. Vapors having sweet smell (fruity smell) are evolved. What type of functional group is present in this organic compound? The structural formula of an ester is:
Answer
When a neutral organic compound is warmed with ethanoic acid in the presence of
concentrated H2SO4, and sweet-smelling vapour are produced, it indicates the formation of an ester. This reaction is called esterification.
The organic compound contains carbonyl group (C=O).
Structural formula of an ester
R-COO-R
Q9. An organic acid ‘X’ is a liquid, which often freezes during winter time in cold countries, having the molecular formula C2H4O2. On warming it with methanol in the presence of a few drops of concentrated sulphuric acid, a compound ‘Y’ with a sweet smell is formed.
(a) Identify ‘X’ and ‘Y’. also write their formulae showing the functional group present in them.
(b) Write the chemical equation for the reaction involved.
Answer
The organic acid X with molecular formula C2H4O2 that freezes in cold weather is Ethanoic acid (Acetic acid). When ethanoic acid reacts with methanol in the presence of concentrated H2SO4, a sweet-smelling ester is formed.
(a) X= Ethanoic acid
Formula = CH3COOH
Y= Methyl ethanoate (ester)
Formula = CH3COOCH3
H2SO4
(b) CH3COOH + CH3OH →CH3COOCH3 + H2O
This reaction is called Esterification.
Q10. Which of the following hydrocarbons can decolorise bromine water and which cannot? Why?
C6H12, C6H14, C6H10
Answer
Unsaturated hydrocarbon (alkenes and alkynes) decolorise bromine water, while saturated hydrocarbons (alkanes) do not decolorise bromine water.
Explanation
(i) Unsaturated hydrocarbons contain double or triple bonds. These bonds react with bromine in an addition reaction, which causes the brown colour of bromine water to disappear.
(ii) Saturated hydrocarbons contain only single bonds and do not react with bromine water, so the colour remains unchanged.
Related Topics
1. NIOS Class 10 Science Worksheets Solution Set 1
2. NIOS Class 10 Science Worksheets Solution Set 2