Question 1

Which reagent would cause the following conversion to take place?

Accepted Answer

A)  Excess CH3OH and KOH 
B)  Excess CH3OH and HCl 
C)  Excess (CH3)2SO4 and OH- 
D)  Excess CH3I and H3O+ 
E)  Excess (CH3CO)2O 
A)  Excess CH3OH and KOH 
B)  Excess CH3OH and HCl 
C)  Excess (CH3)2SO4 and OH- 
D)  Excess CH3I and H3O+ 
E)  Excess (CH3CO)2O

Question 2

Cellulose differs from chitin in which way?

Accepted Answer

A)  Cellulose has $\beta$-glycosidic linkages;chitin has $\infty$-glycosidic linkages. 
B)  Cellulose contains only D-glucose units;chitin contains only N-acetyl-D-glucosamine units. 
C)  Cellulose cannot be hydrolyzed;chitin can be hydrolyzed. 
D)  Cellulose has a linear structure;chitin has a helical structure. 
E)  Cellulose chains are branched;chitin chains are unbranched. 
A)  Cellulose has $\beta$-glycosidic linkages;chitin has $\infty$-glycosidic linkages. 
B)  Cellulose contains only D-glucose units;chitin contains only N-acetyl-D-glucosamine units. 
C)  Cellulose cannot be hydrolyzed;chitin can be hydrolyzed. 
D)  Cellulose has a linear structure;chitin has a helical structure. 
E)  Cellulose chains are branched;chitin chains are unbranched.

Question 3

Which reagent would be used for the following transformation?

Accepted Answer

A)  CH3I,KOH 
B) 
  
C)  (CH3)2SO4,NaOH 
D)  CH3OH,HCl 
E) 
  
A)  CH3I,KOH 
B) 
  
C)  (CH3)2SO4,NaOH 
D)  CH3OH,HCl 
E)

Question 4

Consider the structure of D-erythrose,shown below.Draw the structure of the product obtained upon treatment of D-erythrose with nitric acid.Give its IUPAC name and comment on its stereochemistry.

Accepted Answer

The product,2,3-dihydroxybutan

Question 5

What is the ratio of products formed by the reaction of periodic acid with the following compound?   H2C=O HCO2H
CO2
I
5
1
0
II
3
3
0
III
1
5
0
IV
1
4
1
V
0
4
2

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 6

Suggest a simple chemical test that you might use to distinguish between 2,3-pentanediol and 2,4-pentanediol?

Accepted Answer

Periodic acid test: 2,3- pentanediol is

Question 7

Consider the structures shown below.Which structure represents $\beta$-D-glucopyranose?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 8

Ordinary table sugar is a disaccharide called __________.

Accepted Answer

The answer of Ordinary table sugar is a disaccharide called...

Question 9

Sucrose reacts with which of these reagents?

Accepted Answer

A)  C6H5NHNH2 
B)  Cu2+ 
C)  Br2/H2O 
D)  H3O+ 
E)  Ag(NH3)2+ 
A)  C6H5NHNH2 
B)  Cu2+ 
C)  Br2/H2O 
D)  H3O+ 
E)  Ag(NH3)2+

Question 10

Bromine water is a reagent that converts an aldose to an ___________.

Accepted Answer

The answer of Bromine water is a reagent that converts...

Question 11

Consider the structures shown below.Which compound is not a reducing sugar?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 12

Consider the structures below: what term(s)describe(s)the relationship between them?

Accepted Answer

A)  Enantiomers 
B)  Epimers 
C)  Diastereomers 
D)  Anomers 
E)  More than one of the above 
A)  Enantiomers 
B)  Epimers 
C)  Diastereomers 
D)  Anomers 
E)  More than one of the above

Question 13

Which of these is a non-reducing monosaccharide?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 14

Which of these is a component of the mixture formed when D-galactose is placed in aqueous base (de Bruyn - van Ekenstein transformation)?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 15

Refer to the structures below.Which are L-sugars?

Accepted Answer

A)  II and IV 
B)  I,II,and III 
C)  I and V 
D)  III,IV,and V 
E)  IV and V 
A)  II and IV 
B)  I,II,and III 
C)  I and V 
D)  III,IV,and V 
E)  IV and V

Question 16

Which of the following would give a positive test with Benedict's solution?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  All of these 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  All of these

Question 17

Which compound is D-galactose?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 18

Many carbohydrates exist in equilibrium with cyclic hemiacetals.Those carbohydrates that form a five-membered cyclic hemiacetal are called _____________.

Accepted Answer

The answer of Many carbohydrates exist in equilibrium with cyclic...

Question 19

Lactose exists in two forms α and β.Anomer α has [α]D = +92.6o,and anomer β has [α]D = +34o.What are the percentages of each anomer at equilibrium when the specific rotation of the water solution is + 52o?

Accepted Answer

Percentage of the anomer β at

Question 20

Which is a ketohexose?

Accepted Answer

A)  D-Glucose 
B)  D-Fructose 
C)  D-Mannose 
D)  D-Ribose 
E)  (+)-Sucrose 
A)  D-Glucose 
B)  D-Fructose 
C)  D-Mannose 
D)  D-Ribose 
E)  (+)-Sucrose

Exam 22: Carbohydrates

Which reagent would cause the following conversion to take place?

Cellulose differs from chitin in which way?

Which reagent would be used for the following transformation?

Consider the structure of D-erythrose,shown below.Draw the structure of the product obtained upon treatment of D-erythrose with nitric acid.Give its IUPAC name and comment on its stereochemistry.

What is the ratio of products formed by the reaction of periodic acid with the following compound? H2C=O HCO2H CO2 I 5 1 0 II 3 3 0 III 1 5 0 IV 1 4 1 V 0 4 2

Suggest a simple chemical test that you might use to distinguish between 2,3-pentanediol and 2,4-pentanediol?

Consider the structures shown below.Which structure represents β\betaβ -D-glucopyranose?

Ordinary table sugar is a disaccharide called __________.

Sucrose reacts with which of these reagents?

Bromine water is a reagent that converts an aldose to an ___________.

Consider the structures shown below.Which compound is not a reducing sugar?

Consider the structures below: what term(s)describe(s)the relationship between them?

Which of these is a non-reducing monosaccharide?

Which of these is a component of the mixture formed when D-galactose is placed in aqueous base (de Bruyn - van Ekenstein transformation)?

Refer to the structures below.Which are L-sugars?

Which of the following would give a positive test with Benedict's solution?

Which compound is D-galactose?

Many carbohydrates exist in equilibrium with cyclic hemiacetals.Those carbohydrates that form a five-membered cyclic hemiacetal are called _____________.

Lactose exists in two forms α and β.Anomer α has [α]D = +92.6o,and anomer β has [α]D = +34o.What are the percentages of each anomer at equilibrium when the specific rotation of the water solution is + 52o?

Which is a ketohexose?

Carbon Compounds and Chemical Bonds

Representative Carbon Compounds: Functional Groups, Intermolecular Forces, and Infrared Ir Spectroscopy

An Introduction to Organic Reactions: Acids and Bases

Alkanes: Nomenclature, Conformational Analysis, and an Introduction to Synthesis

Stereochemistry: Chiral Molecules

Ionic Reactions - Nucleophilic Substitution and Elimination Reactions of Alkyl Halides

Alkenes and Alkynes I: Properties and Synthesis, Elimination Reactions of Alkyl Halides

Alkenes and Alkynes Ii: Addition Reactions

Nuclear Magnetic Resonance and Mass Spectrometry: Tools for Structure Determination

Radical Reactions

Alcohols and Ethers

Alcohols From Carbonyl Compounds Oxidation-Reduction and Organometallic Compounds

Conjugated Unsaturated Systems

Aromatic Compounds

Reactions of Aromatic Compounds

Aldehydes and Ketones I Nucleophilic Addition to the Carbonyl Group

Aldehydes and Ketones Ii Aldol Reactions

Carboxylic Acids and Their Derivatives Nucleophilic Addition - Elimination at the Acyl Carbon

Synthesis and Reactions of Beta-Dicarbonyl Compounds: More Chemistry of Enolate Ions

Amines

Phenols and Aryl Halides: Nucleophilic Aromatic Substitution

Lipids

Amino Acids and Proteins

Nucleic Acids and Protein Synthesis

Filters

What is the ratio of products formed by the reaction of periodic acid with the following compound? H₂C=O HCO₂H CO₂ I 5 1 0 II 3 3 0 III 1 5 0 IV 1 4 1 V 0 4 2

Consider the structures shown below.Which structure represents $\beta$ -D-glucopyranose? $Consider the structures shown below.Which structure represents \beta -D-glucopyranose?$

Lactose exists in two forms α and β.Anomer α has [α]_D = +92.6^o,and anomer β has [α]_D = +34^o.What are the percentages of each anomer at equilibrium when the specific rotation of the water solution is + 52^o?