Assertion Reason Chemistry Chapter 4 The d- and f- Block Elements
Questions of Assertion Reason of Chemistry Chapter 4 The d- and f- Block Elements CBSE Class 12 are very simple to understand as this chapter deals with The d- and f- Block Elements. To solve assertion reason type questions of Chemistry, a deeper understanding of concept about Position in the Periodic Table, Electronic Configurations of the d-Block Elements, General Properties of the Transition Elements (d-Block), Some Important Compounds of Transition Elements, The Lanthanoids, The Actinoids and Some Applications of d- and f-Block Elements 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 Chemistry: Chapter 4 The d- and f- Block Elements
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 : Cuprous ion ( Cu^{+} ) has unpaired electrons while cupric ion ( Cu^{++} ) does not.
Reason : Cuprous ion ( Cu^{+} ) is colourless whereas cupric ion ( Cu^{++} ) is blue in the aqueous solution.
Ans.1. (b)
Both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
Question.2.
Assertion : Transition metals show variable valency.
Reason : Transition metals have a large energy difference between the ns^{2} and (n–1)d electrons.
Ans.2. (c)
Assertion is correct but Reason is incorrect.
Question.3.
Assertion : Transition metals are good catalysts.
Reason : V_{2}O_{5} or Pt is used in the preparation of H_{2}SO_{4} by contact process.
Ans.3. (a)
Both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
Question.4.
Assertion : Magnetic moment values of actinides are lesser than the theoretically predicted values.
Reason : Actinide elements are strongly paramagnetic
Ans.4. (d)
Assertion and Reason are incorrect.
