Questions of Assertion Reason Chapter 4 Carbon and Its Compounds Science CBSE Class 10 are very simple to understand as this chapter deals with carbon and its compounds. To solve assertion reason type questions of science, deeper understanding of concept about Carbon bonding and its properties is required. In order to help the student in solving Assertion Reason type of questions, detailed process is explained.
How to solve Assertion Reason Type Questions?
In Assertion-Reason type of question, two statements are given, first is Assertion and second is called Reason. Student must have to think critically about both the statements in Assertion Reason Questions, since it combines multiple choice questions and true/false type of questions which requires a higher level of understanding.
How many types are there of Assertion Reason Type Questions?
Assertion-Reason type of questions can be asked either with four MCQ options or with five MCQ options. First four options are same in both the cases only one more options is being provided i.e. last one. One extra option increases the difficulty level of the questions.
In assertion reason type of questions, all 4 or 5 options are same for each question, which are as:
(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
(e) Both Assertion and Reason are false.
Then a question haunts in every student’s mind, which option is correct and when?
This can be understood clearly with the following table:
| Assertion (A) | Reason (R) | MCQ Options (Fixed for all questions) |
|---|---|---|
| If True | True | (a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A). |
| If True | True | (b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A). |
| If True | False | (c) Assertion (A) is true but reason (R) is false. |
| If False | True | (d) Assertion (A) is false but reason (R) is true. |
| If False | False | (e) Both Assertion and Reason are false. |
Now, lets practice some Assertion Reason Questions of Science Chapter 4 Carbon and Its Compounds.
Read instructions carefully before answering the questions.
For question given below, two statements are given- one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both A and R are true and R is correct explanation of the assertion.
(b) Both A and R are true but R is not the correct explanation of the assertion.
(c) A is true but R is false.
(d) A is false but R is true.
Question.1.
Assertion: Saturated hydrocarbons are chemically less reactive.
Reason: All the valencies of carbon atom are satisfied by single covalent bonds.
Ans.1. (a)
Question.2.
Assertion: Both aldehydes and ketones contain carbonyl group.
Reason: In aldehydes, the functional group is attached to atleast one hydrogen atom.
Ans.2. (b)
Question.3.
Assertion: In alkanes, alkenes and alkynes the valency of carbon is always four.
Reason: All hydrocarbons except alkanes contain double bonds.
Ans.3. (c)
Only alkenes contain double bond, alkynes contain triple bond, but in all hydrocarbons carbon remains tetravalent.
Question.4.
Assertion: Graphite is a good conductor of electricity.
Reason: It has one free valence electron.
Ans.4. (a)
Question.5.
Assertion: The functional group present in alcohols is -OH .
Reason: It is the same group as present in water, hence water and alcohol have similar properties.
Ans.5. (c)
In alcohols -OH group is attached to an alkyl group hence water and alcohol have different properties.
Question.6.
Assertion: Ethanol is first member of the alcohol homologous series.
Reason: A homologous series can be represented by a general formula.
Ans.6. (d)
Methanol is first member of the alcohol
Question.7.
Assertion: Carbon and its compounds can be used as fuels.
Reason: They are highly inflammable and have high calorific value.
Ans.7. (a)
Question.8.
Assertion: Diamond is not good conductor of electricity.
Reason: It has no free electrons.
Ans.8. (a)
In diamond, one carbon atom is attached to four other carbon atoms, hence it has no free electron.
Question.9.
Assertion: Covalent compounds are generally poor conductor of electricity.
Reason: They consist of molecules and not ions which can transfer charge.
Ans.9. (a)
Question.10.
Assertion: Carbon possesses property of catenation.
Reason: Carbon atoms form double as well as triple bonds during catenation.
Ans.10. (b)
Catenation property of carbon is primarily due to its small size, electronic configuration and unique strength of carbon-carbon bonds.
Question.11.
Assertion: Two members of a homologous series have similar chemical properties.
Reason: Propane and butane are members of same homologous series.
Ans.11. (b)
All the members of homologous series contain the same functional group, show gradation in physical properties and similarity in chemical properties.
Question.12.
Assertion: Olefins have the general formula C_{n}H_{2n+1} .
Reason: There is atleast one double bond between two carbon atoms in their molecules.
Ans.12. (d)
Olefins are unsaturated hydrocarbons. There is at least one double bond between two carbon atoms in their molecules and they have the general formula C_{n}H_{2n} .
Question.13.
Assertion: Diamond is the hardest natural known substance.
Reason: Diamond is used for cutting marble, granite and glass.
Ans.13. (b)
Question.14.
Assertion: Diamond and graphite do not have the same crystal structure.
Reason: Diamond is crystalline while graphite is amorphous.
Ans.14. (c): In diamond, C-atoms are sp^{3} hybridized while in graphite, they are sp^{2} hybridized. Diamond and graphite both are crystalline forms of carbon.
Question.15.
Assertion: Graphite is soft and slippery to touch.
Reason: Graphite has sheet like layered structure.
Ans.15. (a)