NCERT Class 11 Solutions Organic Chemistry

Scroll down for PDF

NCERT Class 11 Solutions Organic Chemistry - NCERT Solutions prepared for CBSE students by the best teachers in Delhi.

Chapter 12 – Organic Chemistry Some Basic Principles and Techniques

Class XI Chemistry

Question 12.5: Which of the following represents the correct IUPAC name for the compounds concerned? (a) 2,2-Dimethylpentane or 2-Dimethylpentane (b) 2,4,7-Trimethyloctane or 2,5,7-Trimethyloctane (c) 2-Chloro-4-methylpentane or 4-Chloro-2-methylpentane (d) But-3-yn-1-ol or But-4-ol-1-yne

Answer:

(a) The prefix di in the IUPAC name indicates that two identical substituent groups are present in the parent chain. Since two methyl groups are present in the C–2 of the parent chain of the given compound, the correct IPUAC name of the given compound is 2, 2–dimethylpentane.

(b) Locant number 2, 4, 7 is lower than 2, 5, 7. Hence, the IUPAC name of the given compound is 2, 4, 7–trimethyloctane.

(c) If the substituents are present in the equivalent position of the parent chain, then the lower number is given to the one that comes first in the name according to the alphabetical order. Hence, the correct IUPAC name of the given compound is 2–chloro– 4–methylpentane.

(d) Two functional groups – alcoholic and alkyne – are present in the given compound. The principal functional group is the alcoholic group. Hence, the parent chain will be suffixed with ol. The alkyne group is present in the C–3 of the parent chain. Hence, the correct IUPAC name of the given compound is But–3–yn–1–ol.

Question 12.6: Draw formulas for the first five members of each homologous series beginning with the following compounds. (a) H–COOH (b) CH3COCH3 (c) H–CH=CH2

Answer :The first five members of each homologous series beginning with the given compounds are shown as follows:

(a)

H–COOH : Methanoic acid

CH3–COOH : Ethanoic acid

CH3–CH2–COOH : Propanoic acid

CH3–CH2–CH2–COOH : Butanoic acid

CH3–CH2–CH2–CH2–COOH : Pentanoic acid

(b)

CH3COCH3 : Propanone

CH3COCH2CH3 : Butanone

CH3COCH2CH2CH3 : Pentan-2-one

CH3COCH2CH2CH2CH3 : Hexan-2-one

CH3COCH2CH2CH2CH2CH3 : Heptan-2-one

(c)

H–CH=CH2 : Ethene

CH3–CH=CH2 : Propene

CH3–CH2–CH=CH2 : 1-Butene

CH3–CH2–CH2–CH=CH2 : 1-Pentene

CH3–CH2–CH2–CH2–CH=CH2 : 1-Hexene

For more study material for Chemistry please click here - states of matter class 11 notes pdf.

Question 12.7: Give condensed and bond line structural formulas and identify the functional group(s) present, if any, for :

(a) 2,2,4-Trimethylpentane

(b) 2-Hydroxy-1,2,3-propanetricarboxylic acid

(c) Hexanedial

Question 12.9: Which of the two: O2NCH2CH2O– or CH3CH2O– is expected to be more stable and why?

Answer: NO2 group is an electron-withdrawing group. Hence, it shows –I effect. By withdrawing the electrons toward it, the NO2 group decreases the negative charge on the compound, thereby stabilising it. On the other hand, ethyl group is an electron-releasing group. Hence, the ethyl group shows +I effect. This increases the negative charge on the compound, thereby destabilising it. Hence, O2NCH2CH2O– is expected to be more stable than CH3CH2O– .

Question 12.10: Explain why alkyl groups act as electron donors when attached to a π system.

Answer When an alkyl group is attached to a π system, it acts as an electron-donor group by the process of hyperconjugation. To understand this concept better, let us take the example of propene.


Students should free download the NCERT solutions and get better marks in exams. Studiestoday.com panel of teachers recommend students to practice questions in NCERT books and download NCERT solutions.

Tags: 


Click on the text For more study material for Chemistry please click here - Chemistry

Latest NCERT & CBSE News

Read the latest news and announcements from NCERT and CBSE below. Important updates relating to your studies which will help you to keep yourself updated with latest happenings in school level education. Keep yourself updated with all latest news and also read articles from teachers which will help you to improve your studies, increase motivation level and promote faster learning

Vidya Daan by CBSE

CBSE has launched a new initiative to provide free of cost quality education to students in rural areas. CBSE has named that initiative “Vidya Daan”. Lot of reforms are been continuously done by CBSE so that the teachers can offer a personalized experience to students...

CBSE Board Exams Changes to be implemented in exam pattern

CBSE Board Exams Class 10 & 12 2020: Changes to be implemented in exam pattern Are you appearing for the CBSE Class 10 and 12 Board Exams 2020? If yes, then you have to check out what CBSE has brought the major changes for the CBSE class 10 and 12 board exams 2020...

CBSE schools to participate in National Assessment

CBSE schools to participate in National Assessment for Scientific Temperament and Aptitude According to the latest reports, CBSE has asked all its affiliated schools to encourage and motivate the students to participate in a national assessment programme which is...

UP government schools will follow NCERT

UP government schools will follow NCERT pattern from April 2020Are you appearing for the UP exams 2020? If yes, then you have to see what major changes UP government schools have brought for 2020.The UP government is fully prepared to implement NCERT pattern for...

CBSE Board Exams 2020 Attendance rules revised for Class 10 and 12 students

CBSE Board Exams 2020: Attendance rules revised for Class 10, 12 students : The Central Board of Secondary Education (CBSE) has announced new rules to deal with the cases of short attendance of students of all its affiliated schools. The board has issued a set of...

JEE Main registration 2020 List of qualifying exams

JEE Main registration 2020: List of qualifying exams The process of JEE (Joint Entrance Examination) Main has already been started from September 3, 2019, on the official website of JEE, i.e. jeemain.nic.in. The interested and eligible students can also apply for JEE...

×
Studies Today