Concept explainers
Compound | Molecular formula before hydrogenation | Molecular formula after hydrogenation | Number of rings | Number of pi bonds |
A |
|
|
? | ? |
B | ? |
|
|
|
C |
|
? |
|
? |
Complete the missing information for compounds A, B, and C, each subjected to hydrogenation.
The number of rings and π bonds refers to the reactant (A, B, or C) prior to hydrogenation.
Interpretation: The missing information in the given table is to be completed.
Concept introduction: Degree of unsaturation is used to determine the total number of rings and pi bonds present in compound by just looking at the molecular formula. It does not specify the total number of rings and total number of pi bonds individually.
Answer to Problem 12.7P
The missing information about compounds A, B and C is completed in the table given below.
Compound | Molecular formula before hydrogenation | Molecular formula after hydrogenation | Number of rings | Number of pi bonds |
A | 2 | 3 | ||
B | 0 | 1 | ||
C | 1 | 2 |
Explanation of Solution
For compound A:
Before hydrogenation, the molecular formula is
The maximum number of
The maximum number of
The number of
Substitute the values of maximum number of
The degree of unsaturation is calculated by the formula,
Hence, the degree of unsaturation before hydrogenation is five. After hydrogenation, the molecular formula is
The maximum number of
The maximum number of
The number
Substitute the values of maximum number of
The degree of unsaturation is calculated by the formula,
Hence, the degree of unsaturation after hydrogenation is three.
The number of pi bonds in A is calculated by the formula,
Substitute the values of degree of unsaturation before hydrogenation and degree of unsaturation after hydrogenation in the above formula.
Hence, the number of pi bonds is two.
Number of rings is calculated by the formula,
Substitute the values of degree of unsaturation and number of pi bonds in the above formula.
Hence, the number of rings is three.
For compound B:
After hydrogenation, the molecular formula is
The maximum number of
The maximum number of
The number of
Since both maximum number of
Hence, the degree of unsaturation after hydrogenation is zero.
The number of pi bonds in B is calculated by the formula,
Substitute the values of number of pi bonds and degree of unsaturation after hydrogenation in the above formula.
Hence, degree of unsaturation before hydrogenation is one.
Before hydrogenation,
The maximum number of
The maximum number of
The degree of unsaturation is calculated by the formula,
Hence, the number of
The number
Substitute the values of maximum number of
Hence, the molecular formula before hydrogenation is
For compound C:
Before hydrogenation, the molecular formula is
The maximum number of
The maximum number of
The number
Substitute the values of maximum number of
The degree of unsaturation is calculated by the formula,
Hence, the degree of unsaturation before hydrogenation is three.
Number of rings is calculated by the formula,
Substitute the values of degree of unsaturation and number of rings in the above formula.
Hence, the number of pi bonds is two.
The degree of unsaturation after hydrogenation is equal to the number of rings present in the compound. Hence, degree of unsaturation after hydrogenation is one.
After hydrogenation,
The maximum number of
The maximum number of
The degree of unsaturation is calculated by the formula,
Hence, the number of
The number
Substitute the values of maximum number of
Hence, the molecular formula before hydrogenation is
The missing information about compounds A, B and C is completed in the table given below.
Compound | Molecular formula before hydrogenation | Molecular formula after hydrogenation | Number of rings | Number of pi bonds |
A | 2 | 3 | ||
B | 0 | 1 | ||
C | 1 | 2 |
Table 1
The missing information about compounds A, B and C is completed in the table 1.
Want to see more full solutions like this?
Chapter 12 Solutions
ORGANIC CHEMISTRY-MOLYMOD PACKAGE
Additional Science Textbook Solutions
Organic Chemistry
Chemistry: An Introduction to General, Organic, and Biological Chemistry (12th Edition) - Standalone book
Chemistry For Changing Times (14th Edition)
General, Organic, and Biological Chemistry: Structures of Life (5th Edition)
Chemistry: Structure and Properties
Organic Chemistry - Standalone book
- Draw the most stable conformation of pentane, using wedges and dashes to represent bonds coming out of the paper and going behind the paper, respectively.arrow_forwardWhich of the following structures are identical? (Green = Cl.)arrow_forward5. (a) Describe the type of reaction below as: addition; elimination; combustion; substitution(i) Cyclohexene + bromine ………………………………………………..(ii) CH3CHCH2 + H2 …………………………………………………...(iii) C6H6 + Br2 ………………………………………………………….(iv) C2H5OH → C2H4 + H2O …………………………………………..(v) C3H8 + 5O2 → 3CO2 +4H2O …………………………………………..arrow_forward
- Indicate whether each statement is true or false. (a) Butanecontains carbons that are sp2 hybridized. (b) Cyclohexaneis another name for benzene. (c) The isopropyl group containsthree sp3-hybridized carbons. (d) Olefin is anothername for alkyne.arrow_forwardskeletal line bond drawing of C6H5CO2H with an aromatic 6 membered ringarrow_forward1,4-Pentadiene (CH2=CH-CH2-CH=CH2) is a liquid at room temperature and has a density of 0.66 g/mL and molar mass of 68.12 g/mol. In a laboratory experiment, 3.80 mL of this compound was treated with 4.80 mL of conc. H2SO4 (100% w/w; molar mass 98.08 g/mol). Note that the density of conc. H2SO4 is 1.84 g/mL. The resulting sulfate ester was then treated with 1.20 mL of water (molar mass 18.02 g/mol) affording, after work- up, 2,4-pentanediol (molar mass 104.15 g/mol) as the crude product. The crude product was then purified by simple distillation, which yielded 2.00 g of pure product. What is the theoretical yield of 2,4-pentanediol expressed in grams? Show calculations. What is the percentage yield of pure 2,4-pentanediol?arrow_forward
- 1,4-Pentadiene (CH2=CH-CH2-CH=CH2) is a liquid at room temperature and has a density of 0.66 g/mL and molar mass of 68.12 g/mol. In a laboratory experiment, 3.80 mL of this compound was treated with 4.80 mL of conc. H2SO4 (100% w/w; molar mass 98.08 g/mol). Note that the density of conc. H2SO4 is 1.84 g/mL. The resulting sulfate ester was then treated with 1.20 mL of water (molar mass 18.02 g/mol) affording, after work- up, 2,4-pentanediol (molar mass 104.15 g/mol) as the crude product. The crude product was then purified by simple distillation, which yielded 2.00 g of pure product. a. Provide a balanced chemical equation to show the reaction between 1,4-pentadiene and sulfuric acid. Do not use molecular formulas in the chemical equation except for sulfuric acid. b. What reactant is the limiting reagent in this chemical equation? Show calculations to support your answer.arrow_forwardIn a tabular format, enumerate 5 molecules where the following atoms are found in: O (sp3-hybridized) Oxygen (sp2-hybridized) Nitrogen (sp2-hybridized) Carbon (sp2-hybridized) O (sp3-hybridized) Oxygen (sp2-hybridized) Nitrogen (sp2-hybridized) Carbon (sp2-hybridized) Hydrogen (H2o)Methanol (CH3OH)Methane (CH4)Carbon (C=C)arrow_forwardDraw the Kekule Structure with lone pairs, the type of organic reaction (addition, elimination, substitution, and rearrangement reaction), and draw the move of electrons of the following: 1. CH3Br + KOH --> CH3OH + KBr 2. CH3CH2Br --> H2C=CH2 + HBrarrow_forward
- Please identify the correct ring flipped structure of compound XYZ.arrow_forwardThe skeletal line formula for a branched alkene is shown below. (i) What is the molecular formula of this compound? (ii) How many carbon atoms are in the longest chain, ignoring the double bond? (iii) What is the longest chain incorporating both carbons of the double bond? (iv) How many substituents are on this chain? (v) Give the IUPAC name for this compound. [6]arrow_forwardWhich of the following molecules has only single bonds. A. CHCHCH3 B. CH2CHCH3 C. CH3CH2CCH D. CH3CH3 E. CH2CH2 Which of the following molecules has a carbon-to-carbon double bond? A. CH3CCH B. CHCH C. CH3CH3 D. CH3CH2CH3 E. CH2CHCH3arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage Learning
- Organic Chemistry: A Guided InquiryChemistryISBN:9780618974122Author:Andrei StraumanisPublisher:Cengage Learning