Question 1

Which of the following skeletal structures represents a ketone?

Accepted Answer

A structure with a carbonyl group ($$C=O) $$bonded to two alkyl groups.

Question 2

Given the skeletal structure below, what is the common name of the ketone?

$$CH_3COCH_2CH_3$$

Accepted Answer

Ethyl methyl ketone

Question 3

What is the condensed structure of the product formed when propanal ($$CH_3CH_2CHO) is $$reduced by $$NaBH_4$$?

Accepted Answer

$$CH_3CH_2CH_2OH$$

Question 4

Which carbon in the following condensed structure is a hemiacetal carbon?

$$CH_3CH(OH)$$OCH_3$$

Accepted Answer

The central carbon bonded to both $$-OH$$ and $$-$$OCH_3$$ groups.

Question 5

Which of the following best distinguishes an aldose from a ketose?

Accepted Answer

An aldose contains an aldehyde group ($$-CHO) at $$the end of the molecule, while a ketose contains a ketone group ($$C=O) $$within the carbon chain.

Question 6

Which of the following molecules is chiral?

Accepted Answer

$$CH_3CH(OH)CH_2CH_3$$

Question 7

Given the Fischer projection of D-glucose, which of the following represents its enantiomer?

Accepted Answer

The Fischer projection with all chiral centers inverted (left and right switched at each chiral carbon).

Question 8

Which of the following is the correct Haworth projection for fructose (a ketose) formed from its Fischer projection?

Accepted Answer

A five-membered ring (furanose) with the anomeric carbon at position 2.

Question 9

Which aldose can be reduced to sorbitol (D-glucitol)?

Accepted Answer

D-glucose

Question 10

What is the IUPAC name for the following condensed structure?

$$CH_3CH_2CHO$$

Accepted Answer

Propanal

Question 11

Which of the following correctly identifies the two monosaccharide units in maltose?

Accepted Answer

Two D-glucose units

Question 12

Which of the following statements is true regarding D and L monosaccharides?

Accepted Answer

D and L refer to the configuration of the chiral carbon farthest from the carbonyl group in the Fischer projection.

Question 13

A patient is given an intravenous solution containing D-glucose. Which property ensures that the solution contains only one enantiomer?

Accepted Answer

The solution is synthesized or purified to contain only the D-isomer, which is the naturally occurring form in humans.

Question 14

Which of the following best describes the reduction of a ketone using $$NaBH_4$$?

Accepted Answer

The ketone is converted to a secondary alcohol.

Question 15

Which of the following is a correct multi-step synthesis for converting an aldehyde to an acetal?

Accepted Answer

React the aldehyde with two equivalents of an alcohol under acidic conditions.

Question 16

Which of the following best describes the difference between a hemiacetal and an acetal carbon?

Accepted Answer

A hemiacetal carbon is bonded to one $$-OH$$ and one $$-OR$$ group, while an acetal carbon is bonded to two $$-OR$$ groups.

Question 17

Which of the following is the correct condensed structure for the reduction product of 2-butanone ($$CH_3COCH_2CH_3) $$with $$NaBH_4$$?

Accepted Answer

$$CH_3CH(OH)CH_2CH_3$$

Question 18

Which of the following statements about Fischer projections is correct?

Accepted Answer

Horizontal lines represent bonds coming out of the plane toward the viewer.

Question 19

Which of the following best describes the relationship between D-glucose and D-mannose?

Accepted Answer

They are epimers, differing at only one chiral center.

Step-by-Step Guidance for GOB Organic Chemistry: Aldehydes, Ketones, and Carbohydrates

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