2 ratings. Answer : Phenols are more acidic than alcohols. These questions and answers have been prepared by expert Class 12 Chemistry teachers based on the latest NCERT Book for Class 12 Chemistry and examination guidelines issued by CBSE, NCERT, and KVS. Register online for Chemistry tuition on Vedantu.com to score more marks in CBSE board examination.
Balbharati solutions for Chemistry 12th Standard HSC for Maharashtra State Board chapter 11 (Alcohols, Phenols and Ethers) include all questions with solution and detail explanation. 1. Alcohols and phenols have huge applications in daily life as well as the industry. Revision notes in exam days is one of the best tips recommended by teachers during exam days. Monochlorination of toluene in sunlight followed by hydrolysis with aq. Lecture 6 Alcohol Phenol and ether class 12 HSC Board || By New Indian era #nie chemistry class 12thby Mustafa Sir#nie #mhtcet #cet #prashantbhaiya #newindia. Question 11: Give reasons for the following: (i) Phenol is more acidic than ethanol. Check the below NCERT Alcohols Phenols and Ethers Class 12 MCQ Questions with Answers available with PDF free download. CBSE Class 12 Chemistry Chapter 11 Important Questions - Free PDF Download. Post Comment. Chemistry II Subject Chosen. e.g., Preparation of Alcohols (i) From alkenes These MCQs on chapter 11 Alcohols, Phenols and Ethers will also help students in understanding the concepts very well. Ordinary spirit used as an antiseptic contains methanol. Q.1. (ii) Boiling point of ethanol is higher in comparison to methoxymethane. The alcohol is (a) butan-1-ol, (b) butan-2-ol (c) 2-methylpropan-1-ol (d) 2,2-dimethylbutynal-1-oI. (Opens a modal) SN1 and SN2 reactions of alcohols. eSaral offers you complete notes of Alcohol, Ether and Phenol Class 12th.eSaral helps the students in clearing and understanding each topic in a better way. Class 12 Chemistry students should refer to the following NCERT Book chapter Alcohols Phenols And Ethers in standard 12. 11.3. Oxidation of alcohols I: Mechanism and oxidation states. Chemical Reactions of Alcohols 1. In this session, MKA Sir is going to discuss Alcohol, Phenol, and Ether for jee mains 2022/23. 2ROH (Alcohol) + 2M 2ROM + H2. The Revision of this chapter is divided into 3 parts: Revision Notes for Class 12 Chemistry Download as PDF. You have learned that the substitution of one or more hydrogen atom (s) from a hydrocarbon by another atom or a group of atoms results in the formation of an entirely new compound having altogether different properties and applications. 17 ratings. Chemistry Worksheets Class 12 on Chapter 11 with Answers - Set 5. Class 10 Class 12. Learn these solved important questions to get more marks in your class tests . Answer : Williamson ether synthesis : Alkyl halide when treated with sodium alkoxide gives dialkyl ether. Please refer to below Exam Question for Class 12 Chemistry Chapter 11 Alcohols, Phenols and Ethers. Multiple Choice Questions are an important part of Term 1 and Term 2 exams for Grade 12 Chemistry . It can be explained on the basis that alcohol on losing H+ ions form alkoxide ion and phenol forms phenoxide ion. Chemistry . Phenol is another class of organic compound in which the hydroxyl group is attached to the carbon in an aromatic ring. Get detailed Class 12th Chemistry Notes to prepare for Boards as well as competitive exams like IIT JEE, NEET etc. (c) 2, 4-Dihydroxytoluene (d) Benzyl alcohol. Answer: . Class 12 RD Sharma Solutions - Chapter 27 Direction . Alcohol is the class of hydrocarbon having a hydroxy group attached to the aliphatic hydrocarbon chain. NCERT Solutions for Class 12 Chemistry Chapter 11 - Free PDF Download. Alcohols and phenols are formed when a hydrogen atom in a . #AlcoholsPhenolsAndEthers #PhysicswallahFor PDF Notes and best Assignments visit @ http://physicswallahalakhpandey.com/Live Classes, Video Lectures, Test Se. Home SELF STUDY Browse Practice Tests Syllabus Doubts . 11 lessons. NaOH yields. And dehydration of alcohol forms Ether. 1 quiz. Class 10 Class 12. 57M watch mins. This will save your time and will be very useful for a quick reference. Ethylene reacts with Baeyer's reagent to give. Oct 2 - Oct 18, 2020. 4.8. Chapter 11: Alcohols, Phenols, and Ethers. Mohammad Kashif Alam. Alcohol contains one or more hydroxyl (OH) group (s) directly attached to a carbon atom (s). The compound which reacts fastest with Lucas reagent at room temperature is (a) Butan-1-ol Facebook. MCQ Questions for Class 12 Chemistry with Answers were prepared based on the latest syllabus and examination pattern issued by CBSE, NCERT and KVS. The revision notes help you revise the whole chapter 11 in minutes. (iii) Partial double bond character is due to the conjugation of unshared electron pair of oxygen with the . Monohydric, Dihydric, and Trihydric are three types of alcohols, based on the hydroxyl group.Revise complete Alcohol, Phenol and Ethers with Prateek Gupta Sir (IIT-Bombay). (b) . MCQ Question for Class 12 Chemistry Chapter 11 Alcohols, Phenols and Ethers. The subsitution of a hydrogen atom in a hydrocarbon by an alkoxy group (R-O/Ar-O) yields another class of compounds known as 'ethers'. These NCERT Solutions for Class 12 Chemistry help the students with some exercises, worksheets and assignments in practising important structures and . Download Paper. You have learned that the substitution of one or more hydrogen atom (s) from a hydrocarbon by another atom or a group of atoms results in the formation of an entirely new compound having altogether different properties and applications. Your email address will not be published. MCQs On Alcohols, Phenols And Ethers with FREE PDF (Alcohols and Phenols) 1.
To Prepare better for CBSE Class XII Ribblu.com. This will clear students doubts about any question and improve application skills while preparing for board exams. In contrast, phenol is the class of hydrocarbon having a hydroxy group attached to the benzene ring. The boiling points of ethers are much lower than, those of alcohol of comparable molar masses because like alcohols they cannot form intermolecular hydrogen bonds. Preparation of Alcohol 1. Very Short Answer Questions : Question. Choose the correct option. by Editor | Chemistry. These MCQ questions for Class 12 Chemistry with answers have been designed as per the latest NCERT, CBSE books and syllabus issued for the current academic year.These objective questions for Alcohols Phenols and Ethers will help you to prepare for the exams and get more marks. Assertion and Reason Questions on Class 12 Chemistry Chapter 11 ALCOHOLS, PHENOLS AND ETHERS Directions: These questions consist of two statements, each printed as Assertion and Reason. H 2 SO 4 gave an alkene Y with formula C 4 H 8. . reddit. Draw the structures of all isomeric alcohols of molecular formula C 5 H 12 O and give their IUPAC names. 2.
NCERT Exemplar Problems Class 12 Chemistry Chapter 11 Alcohols, Phenols and Ethers Multiple Choice Questions Single Correct Answer Type Question 1. Welcome to your Alcohols, Phenols and Ethers MCQs Mock Test of Class 12th Chemistry. Home; Go Premium; Class IX. The appropriate answers are likewise accommodated your reference. An ether contains an alkoxy/aryloxy group (R-O/Ar-O) in place of the H . Trihydric Alcohols Glycerol or glycerine, CH 2 OH - CH (OH)- CH 2 OH is the first member of this group. Method of Preparation It is obtained as a by product in saponification reaction. Ethyl alcohol is industrially prepared from ethylene by. Question. Ethanol is a volatile, flammable . These Alcohols Phenols and Ethers Chemistry Class 12 Notes Handwritten Notes in Pdf will help you to prepare for different competitive exams like NEET, JEE Main, GATE, PSUs, and so on. An alcohol X when treated with hot cone. 1-Ethoxy-2-nitrocyclohexane. NaOH yields. Single Correct Answer Type. Answer. Lecture 6 Alcohol Phenol and ether class 12 HSC Board || By New Indian era #nie chemistry class 12thby Mustafa Sir#nie #mhtcet #cet #prashantbhaiya #newindia. Class 12 Chemistry Notes - Chapter 18 - Alcohol, Phenols and Ethers - MCQs. 1.
Propan1ol undergoes dehydration in the presence of protic acids (such as H 2 SO 4, H 3 PO 4) to give 1-propoxypropane. 3. CBSE 12th Standard Chemistry Subject Alcohols , Phenols and Ethers Chapter Case Study Questions With Solution 2021 - QB365 Provides the updated CASE Study Questions for Class 12 , and also provide the detail solution for each and every case study questions . Question. Physical Properties 1. Chemistry . Share. Preparation of alcohol by fermentation method. Taking these course books as a reference can be really helpful to prepare for any sought exam. Students who are studying in Class 12 and candidates who are preparing for competitive exams can download the PDF for NCERT Class 12 Books Chemistry Chapter 11- Alcohols, Phenols and Ethers to learn from the reading material. (b) Slightly soluble in water. Please refer to Chapter 11 Alcohols Phenols and Ethers MCQ Class 12 Chemistry with answers below. Alcohol by Grignard reagents 4. Practice MCQ Question for Class 12 Chemistry chapter-wise. Maharashtra State Board Class 12 Chemistry Solutions Chapter 11 Alcohols, Phenols and Ethers. Alcohol is the class of hydrocarbon having a hydroxy group attached to the aliphatic hydrocarbon chain. Going through the solutions provided on this page will help you to know how to approach and solve the problems. Chapter 11: Alcohols, Phenols, and Ethers. You have to select one of the codes (a), (b), (c) and (d . NCERT Book for Class 12 Chemistry Chapter 11 Alcohols, Phenols and Ethers is available for reading or download on this page. The mechanism of this reaction involves the following three steps: Step 1: Protonation. MCQ Alcohol Phenol Ether Class 12 Question 15. 2. Its formula can be also written as CH CH OH or C H OH, and is often abbreviated as EtOH. This alkene on ozonolysis gives single product with molecular formula C 2 H 4 O. In this course, Mohammad Kashif Alam will cover Alcohol, Phenol & Ether for Class 12 & Droppers. 2CH3-OH (Methanol) + 2Na 2 CH3-ONa (Sodium methoxide) + H2. Join Telegram:https://t.me/LearnoHub12 Ask Doubts:https://www.examfear.com/question/ Product Details: https://www.amazon.in/stores/page/2EFB8884-9FA4-445. Given below are MCQ Questions for Class 12 Chemistry Alcohols, Phenols and Ethers which will help you with analyze your knowladge on the topics. These multiple-choice questions have been prepared based on the latest NCERT book for Class 12 Chemistry. VBQs for Class 12. Question 1. Submit a Comment. 5. Its IUPAC name is propane-l,2,3-triol. Find here the NCERT chapter-wise Multiple Choice Questions from Class 12 Chemistry book Chapter 11 Alcohols, Phenols and Ethers with Answers Pdf free download. Thus, alcohols phenols and ethers class 12 notes pdf will explain . Currently only available for. Alcohols,Phenols and Ethers Chemistry Practice questions, MCQs, Past Year Questions (PYQs), NCERT Questions, Question Bank, Class 11 and Class 12 Questions, NCERT Exemplar Questions and PDF Questions with answers, solutions, explanations, NCERT reference and difficulty level Question. Chemistry Guide for Class 12 PSEB Alcohols, Phenols, and Ethers Textbook Questions and Answers. NCERT Solutions for Class 12 Chemistry Chapter 11 Alcohols, Phenols and Ethers is an essential study material that is required for all students studying Class 12 Chemistry. 11Unit . Answer: (D) A is false and R is True. (a) Dipolar character of ether. Answer. Free PDF download of Important Questions for CBSE Class 12 Chemistry Chapter 11 - Alcohols, Phenols and Ethers 5 Marks Questions prepared by expert Chemistry teachers from latest edition of CBSE(NCERT) books, On CoolGyan.Org to score more marks in CBSE board examination. Both alcohols and phenols are acidic in nature and hence react with active metal to form metal alkoxides and phenoxides respectively with evolution of hydrogen gas. Students who are preparing for their Class 12 exams must go through NCERT Solutions for Class 12 Chemistry Chapter 11 Alcohols Phenols and Ethers. Ethyl Alcohol which is also commonly known as Ethanol is an organic chemical compound. 3. Annu Kumari. It is a simple alcohol , we drink with the chemical formula CHO. (i) Describe the mechanism of acid dehydration of ethanol to yield ethene. Physical Properties: (a) Boiling point of ethers are much lower than corresponding alcohols because ethers do not form intermolecular H-bonding. Classify the following as primary, secondary and tertiary alcohols: Answer: Primary alcohols (i), (ii), (iii) Secondary alcohols (iv) and (v) Tertiary alcohols (vi) Question 2. Students also can take a free test of the Multiple Choice Questions of Alcohols, Phenols and Ethers. Currently only available for. Class 12 Chemistry Chapter 11 Important Extra Questions Alcohols, Phenols and Ethers Alcohols, Phenols and Ethers Important Extra Questions Very Short Answer Type. Students should refer to Worksheets Class 12 Chemistry Alcohols Phenols and Ethers Chapter 11 provided below with important questions and answers. (d) Inter molecular hydrogen bonding in alcohols. Alcohols, Phenols and Ethers . 8 lessons. Answer. Preparation from alkene compound 2. Read online Alcohols . Ended on Oct 18. It is a colourless, odourless, viscous and hygroscopic liquid. All Alcohols, Phenols and Ethers Class 12 Chemistry Important Questions provided below have been prepared by expert teachers of Standard 12 Chemistry. Alcohols, phenols and ethers are the basic compounds for the formation of detergents, antiseptics and fragrances, respectively. These are the Alcohols Phenols and Ethers class 12 Notes prepared by team of expert teachers. Alcohol Phenol And Ether Class 12 MCQ Chapter 11 Question 5. Also, ether is simply a class of organic compounds. Chemistry Worksheets Class 12 on Chapter 11 with Answers - Set 5. He will discuss all-important questions of Alcohol, Phenol, and Ether and will solve them in a quick manner. NCERT Exemplar Class 12 Chemistry Chapter 11 Alcohols, Phenols and Ethers. (Opens a modal) Preparation of alkyl halides from alcohols. (Opens a modal) Oxidation of alcohols II: Examples. Learn. Nomenclature of Alcohols and Phenol In IUPAC, system, alcohol or alkanols are named by replacing the last word 'e' of the corresponding alkane by 'ol'. Reaction with Metals. The greater acidity of phenol is due to the stability of the phenoxide ion which is resonance stabilized as shown below. Note: In the following questions a statement of assertion followed by a statement of reason is given. LinkedIn. Assertion (A) : The C-O-C bond angle in ethers is slightly less than tetrahedral angle. Directions : Each of these questions contain two statements,Assertion and Reason.
Assertion and Reasoning Questions - Class 12 / By Chemistry Educator Solve Assertion and Reasoning type of questions based on chapter Alcohols, Phenols, and Ethers from class 12 Chemistry CBSE/NCERT. The MCQ Questions for Class 12 Chemistry with answers have been prepared as per the latest syllabus, NCERT books and examination pattern suggested in Standard 12 by CBSE, NCERT and KVS. Moreover, the attachment of this particular group is to the carbon atom (s). Question 1: How to differentiate between alcohol, phenol and ethers? class 12 chemistry best handwritten notes chemistry class 12 handwritten notes pdf handwritten notes for class 12 chemistry pdf Alcohols Phenols and Ethers Handwritten Notes Class 12 Class 12 Chemistry CBSE 2021. Q.1. In contrast, phenol is the class of hydrocarbon having a hydroxy group attached to the benzene ring. 1. Alcohol, phenol and ether are the categories of the hydrocarbons. 11.2. Reaction of alcohols. Class 12 Chemistry Important Questions are the best resource for students which helps in Class 12 board exams. Identify aliylic alcohols in the above examples. Alcohols, Phenols and Ethers Book Chosen. Please refer to below Exam Question for Class 12 Chemistry Chapter 11 Alcohols, Phenols and Ethers. Topics and Subtopics in NCERT Solutions for Class 12 Chemistry Chapter 11 Alcohols Phenols and Ether: 11.1. Account for the following : The boiling points of ethers are lower than isomeric alcohols. Question 1. 3. According to IUPAC system (Unit 12, Class XI), the name of an alcohol is derived from the name of the alkane from which the alcohol is derived, Alcohols Phenols and Ethers is an important chapter in Class 12 as it provides very . ASSERTION-REASON TYPE QUESTIONS. MCQs Based On Class 12 Chemistry Chapter 11 Alcohols, Phenols and Ethers . 1. Read more. All the important topics will be discussed in detail and would. Which of the following statements are correct ? Twitter. Answer: (b) butan-2-ol Hindi Alcohols, Phenols & Ethers (Hindi) Alchols, Phenols and Ethers : Class 12. Students who are studying in Class 12 and candidates who are preparing for competitive exams can download the PDF for NCERT Class 12 Books Chemistry Chapter 11- Alcohols, Phenols and Ethers to learn from the reading material. Multiple Choice Questions. The course includes 11 sessions of 90 minutes each. We have provided Class 12 Chemistry Assignments for all chapters on our website. (iii) (CH 3) 3 COCH 3 on reaction with HI gives CH 3 OH and (CH 3) 3 CI as the main products and not (CH 3) 3 COH and CH 3 I.
These problems and solutions for Chapter 11 Alcohols, Phenols and Ethers Class 12 Chemistry have been prepared as per the latest syllabus and books issued for the current academic year. Free PDF download of Important Questions for CBSE Class 12 Chemistry Chapter 11 - Alcohols, Phenols and Ethers prepared by expert Chemistry teachers from latest edition of CBSE(NCERT) books. 23 Downloads. (i) In phenols, the OH group is attached to sp2 hybridised carbon of an aromatic ring. (b) Alcohols having resonance structures. 10.
Neeraj Virdi. Ether is a class of organic compound in which an oxygen atom is bonded to two allyl or alkyl groups. Answer. 0 questions by educators. Furthermore, the alcohol comprises one or more hydroxyl (OH) groups. Question 1 : Due to ____________ An ether is More Volatile than an Alcohol having the Same Molecular Formula. Reason (R): Due to the repulsive interaction between the two alkyl groups in ethers. eSaral is providing complete chapter notes of Class 11th and 12th both of Physics Chemistry & Mathematics.Besides this . Answer: Answer: (d) Inter molecular hydrogen bonding in alcohols. Below are some of the very important NCERT Alcohols Phenols and Ethers MCQ Class 12 Chemistry Chapter 11 with Answers.
2. Digital NCERT Books Class 12 Chemistry pdf are always handy to use when you do not . These important questions with solutions for Chapter 11 Alcohols Phenols and Ethers have been prepared by expert teachers for Class 12 Chemistry based on the expected pattern . (a) o-Cresol (b) w-Cresol (c) 2, 4-Dihydroxytoluene (d) Benzyl alcohol Solution: (d) Monochlorination of toluene in sunlight gives benzyl chloride. Download Alcohols, Phenols and Ethers NCERT PDF. Give one chemical test to distinguish between the following pairs of compounds. Propene when reacted with water in the presence of H2SO4 gives _________. Taking these course books as a reference can be really helpful to prepare for any sought exam. CBSE Class 12 Chemistry Alcohols Phenols and Ethers MCQs Set B with answers available in Pdf for free download. Report. Class 12 Chemistry Chapter 11 Important Extra Questions Alcohols, Phenols and Ethers Alcohols, Phenols and Ethers Important Extra Questions Very Short Answer Type. Worksheets for Class 12. Students should . Answer: In the case of alcohol (OH) group means a hydroxyl group attached to a carbon atom and in phenol hydroxyl group attached to benzene ring while in ether two carbon groups are attached by a single bond with oxygen. In phenols, the - OH group is attached to Sp2 hybridised carbon and thus, the C - O bond acquires a partial double bond character. On hydrolysis . Alcohols, Phenols and Ethers Notes Class 12 Chemistry Chapter 11. 1propoxypropane can be synthesized from propan1-ol by dehydration. Students should refer to MCQ Questions for Class 12 Chemistry with Answers to score more marks in Grade 12 Chemistry exams. Read the given passage and answer the questions that follow: Alcohols play a very important role in our daily life. Please refer to Alcohols Phenols and Ethers MCQ Questions Class 12 Chemistry below. This pdf is also available here to read online so you dont have to always download the pdf. Draw the structures of all isomeric alcohols of molecular formula C 5 H 12 O and give their IUPAC names. (c) Inter molecular hydrogen bonding in ethers. (b) . This may assist you to understand and check your knowledge about the chapters. (a) o-Cresol (b) w-Cresol. Chemical properties: (a) Cleavage ofC-O bond in ethers: (b) Electrophilic substitution: In this, the alkoxy group activates the aromatic ring and directs the incoming . C. We hope the above multiple choice questions for Class 12 Chemistry for Chapter 11 Alcohols Phenols and Ethers provided above with answers based on the latest syllabus and examination guidelines issued by CBSE, NCERT and KVS are really useful for you. Chemistry II Subject Chosen. Easy notes that contain complete MCQs of the chapter. Q.2. Step 2: Nucleophilic attack. The detailed, step-by-step solutions will help you understand the concepts better and clear your . Ethyl Acohol MCQs with Answers Free 2022. Question i. Students who are in Class 12 or preparing for any exam which is based on Class 12 Chemistry can refer NCERT Book for their preparation. A Phehol contains one or more hydroxyl group (OH) attached to a carbon atom (s) of the benzene ring. Alcohol Phenols and Ethers - MCQs. Alcohols Phenols and Ethers Case-Based Questions. In this unit, we shall discuss the chemistry of three classes of compounds, namely alcohols, phenols and ethers.Alcohols and phenols are formed when a hydrogen atom in a hydrocarbon, aliphatic and aromatic respectively, is replaced by -OH group. Alcohols and phenols are formed when a hydrogen atom in a . Identify allylic alcohols in the above examples. Alcohol, phenol and ether are the categories of the hydrocarbons. (ii) Describe a chemical test to distinguish between ethanol and phenol. Alcohol, Phenol and Ether compounds Prepared by, Mr. Snehal Patel. These questions and answers have been prepared by expert Class 12 Chemistry teachers based on the latest NCERT Book for Class 12 Chemistry and examination guidelines issued by CBSE, NCERT, and KVS. Question 1. When hydroxyl (-OH) group bonds with saturated carbon atom we get Alcohol. Alcohols from carbonyl compounds 3. Case study questions are latest updated question pattern from NCERT, QB365 will helps to get more marks in Exams We have covered entire Class 12 Chemistry, you can get link to all the chapters at the bottom of the page. Please also refer to the NCERT solutions for Class 12 Chemistry to understand the answers of the exercise questions given at the end of this chapter. Classify the following as primary, secondary and tertiary alcohols.
Students can also find NCERT intext, exercises and back of chapter questions. Alcohols, Phenols and Ethers Class 12 MCQs Questions with Answers 2022 :- Hope the information shed above regarding NCERT MCQ Questions for Class 12 Chemistry Chapter 11 Alcohols, Phenols and Ethers with Answers Pdf free download has been useful to an extent. Phenol is more acidic than ethanol. The session will be delivered in Hindi and the same notes will be delivered in English. Ethanol is present in cough syrups, tonics, wine, beer, and whisky, Sugar, starch, cellulose are carbohydrates that also . Answer. Alcohols Phenols And Ethers Class 12 Chemistry NCERT. While answering these questions, you are required to choose any one of the following four responses. Monochlorination of toluene in sunlight followed by hydrolysis with aq. Explore various courses on Alcohols, Phenols & Ethers from India's top educators on Unacademy. Please learn them and let us know if you have any questions. The first step of the acid catalysed hydration of alkenes, involves the protonation of alkene to form a carbocation by electrophilic attack of _______. Alcohols, Phenols and Ethers . Alcohols, Phenols and Ethers Book Chosen. Question 1. 2. Q.3. These Topper's Class scanned notes of Alcohols Phenols and Ethers Chemistry Class 12 Notes Handwritten Notes in Pdf will help you to understand all key concepts. Arrange the following in increasing order of their boiling . 0 practices. Each of these questions also has four alternative choices, only one of which is the correct answer. Balbharti Maharashtra State Board 12th Chemistry Textbook Solutions Chapter 11 Alcohols, Phenols and Ethers Textbook Exercise Questions and Answers. (ii) The carbon - oxygen bond length (136 pm) in phenol is slightly more than that in methanol. C 2 H 5 ONa + C 2 H 5 Cl C 2 H 5 OC 2 H 5 + NaCl. (Hindi) Alcohols, Phenols and Ethers Class 12. Alcohols Phenols and Ethers VBQs Class 12 Chemistry. Required fields are marked * Arrange the following in increasing order of their boiling point: CH 3 CH 2 OH, CH 3 CHO, CH 3 OCH 3 (CBSE AI 2019) Answer: CH 3 OCH 3 < CH 3 CHO < CH 3 CH 2 .