11th Chemistry - Book Back Answers - Unit 12 - English Medium Guides

 

 

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Tamil Nadu Board 11th Standard Chemistry - Unit 12 : Book Back Answers and Solutions

    This post covers the book back answers and solutions for Unit 12 – Chemistry from the Tamil Nadu State Board 11th Standard Chemistry textbook. These detailed answers have been carefully prepared by our expert teachers at KalviTips.com.

    We have explained each answer in a simple, easy-to-understand format, highlighting important points step by step under the relevant subtopics. Students are advised to read and memorize these subtopics thoroughly. Once you understand the main concepts, you’ll be able to connect other related points with real-life examples and confidently present them in your tests and exams.

    By going through this material, you’ll gain a strong understanding of Chemistry Unit 12 along with the corresponding book back questions and answers (PDF format).

Question Types Covered:

• 1 Mark Questions: Choose the correct answer, Fill in the blanks, Identify the correct statement, Match the following 
• 2 Mark Questions: Answer briefly 
• 3, 4, and 5 Mark Questions: Answer in detail

All answers are presented in a clear and student-friendly manner, focusing on key points to help you score full marks.

All the best, Class 11 students! Prepare well and aim for top scores. Thank you!

Unit 12 :Basic Concepts of Chemistry and Chemical Calculations

I. Choose the best answer.

1. For the following reactions
(A) CH₃CH₂CH₂Br + KOH → CH₃–CH= CH₂ + KBr +H₂O
(B) (CH₃)₃CBr + KOH → (CH₃)₃ COH + KBr 

Which of the following statement is correct?
(a) (A) is elimination, (B) and (C) are substitution
(b) (A) is substitution, (B) and (C) are elimination
(c) (A) and (B) are elimination and (C) is addition reaction
(d) (A) is elimination, B is substitution and (C) is addition reaction.
Answer Key:
(d) (A) is elimination, B is substitution and (C) is addition reaction.
 
2. What is the hybridisation state of benzyl carbonium ion?
(a) sp²
(b) spd²
(c) sp³
(d) sp²d
Answer Key:
(a) sp²
 
3. Decreasing order of nucleophilicity is
(a) OH^- > NH₂^- > ^-OCH₃ > RNH₂
(b) NH₂^- > OH^- > ^-OCH₃ > RNH₂
(c) NH₂^- > CH₃O^- > OH^- > RNH₂
(d) CH₃O^- > NH₂^- > OH^- > RNH₂
Answer Key:
(b) NH₂^- > OH^- > ^-OCH₃ > RNH₂
 
4. Which of the following species is not electrophilic in nature?
(a) Cl+
(b) BH₃
(c) H₃O⁺
(d) ⁺NO₂
Answer Key:
(c) H₃O⁺
 
5. Homolytic fission of covalent bond leads to the formation of
(a) electrophile
(b) nucleophile
(c) Carbo cation
(d) free radical
Answer Key:
(d) free radical
 
6. Hyper Conjugation is also known as
(a) no bond resonance
(b) Baker - nathan effect
(c) both (a)and (b)
(d) none of these
Answer Key:
(c) both (a)and (b)
 
7. Which of the group has highest +I effect?
(a) CH₃^-
(b) CH₃^-CH₂^-
(c) (CH₃)₂^-CH^-
(d) (CH₃)₃^-C^-
Answer Key:
(d) (CH₃)₃^-C^-
 
8. Which of the following species does not exert a resonance effect?
(a) C₆H₅OH
(b) C₆H₅Cl
(c) C₆H₅NH₂
(d) ${\mathbf{C}}_{\mathbf{6}}{\mathbf{H}}_{\mathbf{5}}\stackrel{\mathbf{+}}{\mathbf{N}}{\mathbf{H}}_{\mathbf{3}}$
Answer Key:
(d) ${\mathbf{C}}_{\mathbf{6}}{\mathbf{H}}_{\mathbf{5}}\stackrel{\mathbf{+}}{\mathbf{N}}{\mathbf{H}}_{\mathbf{3}}$
 
9. -I effect is shown by
(a) -Cl
(b) -Br
(c) both (a) and (b)
(d) -CH₃
Answer Key:
(c) both (a) and (b)
 
10. Which of the following carbocation will be most stable?
(a) Ph3C-⁺
(b) $\mathbf{C}{\mathbf{H}}_{\mathbf{3}}\mathbf{-}\stackrel{\mathbf{+}}{\mathbf{C}}{\mathbf{H}}_{\mathbf{2}}\mathbf{-}$
(c) $\mathbf{(}\mathbf{C}{\mathbf{H}}_{\mathbf{3}}{\mathbf{)}}_{\mathbf{2}}\mathbf{-}\stackrel{\mathbf{+}}{\mathbf{C}}\mathbf{H}$
(d) $\mathbf{C}{\mathbf{H}}_{\mathbf{2}}\mathbf{=}\mathbf{C}\mathbf{H}\mathbf{-}\stackrel{\mathbf{+}}{\mathbf{C}}{\mathbf{H}}_{\mathbf{2}}$
Answer Key:
(a) Ph3C-⁺
 
11. Assertion: Tertiary Carbocations are generally formed more easily than primary Carbocations ions.
Reason: Hyper conjugation as well as inductive effect due to additional alkyl group stabilize tertiary carbonium ions.
(a) both assertion and reason are true and reason is the correct explanation of assertion.
(b) both assertion and reason are true but reason is not the correct
explanation of assertion.
(c) Assertion is true but reason is false
(d) Both assertion and reason are false
Answer Key:
(a) both assertion and reason are true and reason is the correct explanation of assertion.
 
12. Heterolytic fission of C–C bond results in the formation of
(a) free radical
(b) Carbanion
(c) Carbocation
(d) Carbanion and Carbocation
 Answer Key:
(d) Carbanion and Carbocation
 
13. Which of the following represent a set of nuclephiles?
(a) BF₃, H₂O, NH^2-
(b) AlCl₃, BF₃, NH₃
(c) CN^-, RCH₂^-, ROH
(d) H⁺, RNH₃⁺, CCl₂
Answer Key:
(c) CN^-, RCH₂^-, ROH
 
14. Which of the following species does not acts as a nucleophile?
(a) ROH
(b) ROR
(c) PCl₃
(d) BF₃
Answer Key:
(d) BF₃
 
15. The geometrical shape of carbocation is
(a) Linear
(b) tetrahedral
(c) Planar
(d) Pyramidal
Answer Key:
(c) Planar

 

II. Short Answer Questions

11th Chemistry

III. Long Answer Questions

11th Chemistry

IV. Exercise

11th Chemistry