Question 1

Which of the following compounds is an aldehyde? A) CH₃CH₂CH₂COOH B) CH₃CH₂CHO C) CH₃CH₂CH₂OH D) CH₃CH₂COCH₃

Accepted Answer

Aldehydes have the functional group -CHO. Option B correctly represents an aldehyde with this functional group at the end of the carbon chain.

Question 2

What is the ground-state electronic configuration of a fluorine atom (fluorine: atomic number 9)? A) 1s¹2s¹2p⁷ B) 1s²2s²2p⁵ C) 1s²2s²2p⁶ D) 1s⁰2s²2p⁷

Accepted Answer

B

Question 3

Which of the following compounds is a ketone? A) CH₃CH₂COOH B) CH₃CH₂CHO C) CH₃CH₂CH₂OH D) CH₃COCH₃

Accepted Answer

Ketones are characterized by the presence of a carbonyl group (C=O) bonded to two carbon atoms. Option D represents a ketone structure, where the carbonyl group is flanked by two carbon chains.

Question 4

Which of the following is a primary amine? A) CH₃CH₂NHCH₃ B) CH₃CH₂NHCH(CH₃)₂ C) CH₃CH₂N(CH₃)₂ D) (CH₃)₃CNH₂

Accepted Answer

A primary amine has one alkyl or aryl group attached to the nitrogen atom. In option D, (CH₃)₃CNH₂, the nitrogen is attached to one alkyl group, making it a primary amine.

Question 5

Which of the following species possesses a formal charge? A) CCl₄ B) SiCl₄ C) AlCl₄ D) PCl₃

Accepted Answer

AlCl₄ (AlCl4-) has a formal charge because aluminum normally forms three bonds and has no lone pairs, giving it a formal charge of 0 in its neutral state. When it forms four bonds as in AlCl4-, it carries a negative formal charge.

Question 6

How many electrons can the shell with a principal quantum number of 2 hold?
A) 1
B) 2
C) 4
D) 8

Accepted Answer

The shell with a principal quantum number of 2 can hold a maximum of 8 electrons, according to the formula 2n^2, where n is the principal quantum number.

Question 7

What is the ground-state electronic configuration of a nitrogen atom (nitrogen: atomic number 7)? A) 1s²2s¹2p⁴ B) 1s²2s²2p³ C) 1s¹2s¹2p⁵ D) 1s²2s²2p²

Accepted Answer

The correct electronic configuration for a nitrogen atom, which has an atomic number of 7, is 1s² 2s² 2p³. This configuration shows that nitrogen has two electrons in the 1s orbital, two electrons in the 2s orbital, and three electrons in the 2p orbitals, totaling seven electrons.

Question 8

Which of the following species has an atom that has an unfilled valence shell of electrons? A) molecular hydrogen, H₂ B) hydroxide anion, HO− C) boron trifluoride, BF₃ D) water, H₂O

Accepted Answer

Boron trifluoride (BF3) has a boron atom with only six electrons in its valence shell, making it an example of a species with an unfilled valence shell. Boron typically desires eight electrons to satisfy the octet rule, but in BF3, it only bonds with three fluorine atoms, leaving its valence shell incomplete.

Question 9

Which of the following compounds is a carboxylic ester? A) CH₃CH₂COOH B) CH₃CH₂OCH₃ C) CH₃CH₂COOCH₃ D) CH₃CH₂COCH₃

Accepted Answer

Carboxylic esters have the functional group COO, where the carbon atom is double-bonded to one oxygen atom and single-bonded to another oxygen atom, which is in turn bonded to an alkyl or aryl group. Option C, CH3CH2COOCH3, correctly represents this structure.

Question 10

Which of the following is a tertiary amine? A) CH₃CH₂N(CH₃)₂ B) (CH₃)₃CNH₂ C) CH₃CH₂NHCH₃ D) CH₃CH₂NHCH(CH₃)₂

Accepted Answer

A tertiary amine is characterized by the presence of three carbon groups attached to the nitrogen atom. Choice A represents a structure where the nitrogen atom is bonded to three carbon groups, making it a tertiary amine.

Question 11

What is the ground-state electronic configuration of a sodium cation (sodium: atomic number 11)? A) 1s²2s²2p⁶3s¹ B) 1s²2s²2p⁵3s¹ C) 1s²2s²2p⁶ D) 1s²2s²2p⁶3s²

Accepted Answer

The ground-state electronic configuration of a sodium cation (Na+) is obtained by removing one electron from the neutral sodium atom. Neutral sodium (Na) has the electronic configuration 1s^2 2s^2 2p^6 3s^1. Removing one electron (the 3s electron) results in 1s^2 2s^2 2p^6, which matches choice C.

Question 12

Which of the following species has an atom that has an unfilled valence shell of electrons? A) molecular bromine, Br₂ B) fluoride anion, F− C) ammonia, NH₃ D) aluminum trichloride, AlCl₃

Accepted Answer

Aluminum trichloride (AlCl3) has an aluminum atom with only six electrons in its valence shell after forming three covalent bonds with chlorine atoms, leaving it with an unfilled valence shell.

Question 13

Which of the following is trigonal planar? A) boron trifluoride, BF₃ B) methyl anion, CH₃− C) methane, CH₄ D) ammonia, NH₃

Accepted Answer

Boron trifluoride (BF3) has a trigonal planar geometry due to its sp2 hybridization, with three bonding pairs and no lone pairs on the central boron atom.

Question 14

How many electrons can the shell with a principal quantum number of 1 hold?
A) 1
B) 2
C) 4
D) 8

Accepted Answer

The shell with a principal quantum number of 1 can hold a maximum of 2 electrons, according to the 2n^2 rule, where n is the principal quantum number. For n=1, 2(1)^2 = 2.

Question 15

Which of the following compounds is an alcohol? A) CH₃CH₂COOH B) CH₃CH₂OCH₃ C) CH₃CH₂CH₂OH D) CH₃CH₂CHO

Accepted Answer

Alcohols are characterized by the presence of a hydroxyl group (-OH) attached to a carbon atom. Option C, with the ending "OH", indicates the presence of a hydroxyl group, making it an alcohol.

Question 16

Which of the following species possesses a formal charge? A) BH₃ B) BH₄ C) CCl₄ D) H₂S

Accepted Answer

BH₄ has a formal charge because it is a tetrahedral anion with an extra electron, giving it a negative charge.

Question 17

Which of the following is a tertiary alcohol? A) CH₃CH₂OCH₃ B) (CH₃)₃COH C) (CH₃)₂CHOH D) CH₃CH₂CH₂OH

Accepted Answer

A tertiary alcohol is one where the hydroxyl group (-OH) is attached to a carbon atom that is connected to three other carbon atoms. In option B, (CH₃)₃COH, the carbon with the -OH group is connected to three methyl groups, making it a tertiary alcohol.

Question 18

What is the ground-state electronic configuration of a fluoride anion (fluorine: atomic number 9)? A) 1s²2s²2p² B) 1s²2s²2p⁵ C) 1s²2s²2p⁶ D) 1s²2s²2p⁷

Accepted Answer

The ground-state electronic configuration of a fluoride anion, which has gained an extra electron compared to neutral fluorine (atomic number 9), is 1s^2 2s^2 2p^6, reflecting a filled valence shell similar to the noble gas neon. This corresponds to option C when decoded from the given format.

Question 19

Which of the following compounds is a ketone? A) CH₃CH₂COOH B) CH₃CH₂CHO C) CH₃CH₂CH₂OH D) CH₃COCH₃

Accepted Answer

Ketones are characterized by the presence of a carbonyl group (C=O) bonded to two carbon atoms. Option D, represented as CH3COCH3, fits this description, making it a ketone.

Question 20

Which of the following compounds is a carboxylic acid? A) CH₃CH₂COOH B) CH₃CH₂OCH₃ C) CH₃CH₂CH₂OH D) CH₃CH₂CHO

Accepted Answer

The compound with the formula ending in COOH is a carboxylic acid.

Quiz 1: Covalent Bonding and Shapes of Molecules

Which of the following compounds is an aldehyde?

What is the ground-state electronic configuration of a fluorine atom (fluorine: atomic number 9) ?

Which of the following compounds is a ketone?

Which of the following is a primary amine?

Which of the following species possesses a formal charge?

How many electrons can the shell with a principal quantum number of 2 hold?

What is the ground-state electronic configuration of a nitrogen atom (nitrogen: atomic number 7) ?

Which of the following species has an atom that has an unfilled valence shell of electrons?

Which of the following compounds is a carboxylic ester?

Which of the following is a tertiary amine?

What is the ground-state electronic configuration of a sodium cation (sodium: atomic number 11) ?

Which of the following species has an atom that has an unfilled valence shell of electrons?

Which of the following is trigonal planar?

How many electrons can the shell with a principal quantum number of 1 hold?

Which of the following compounds is an alcohol?

Which of the following species possesses a formal charge?

Which of the following is a tertiary alcohol?

What is the ground-state electronic configuration of a fluoride anion (fluorine: atomic number 9) ?

Which of the following compounds is a ketone?

Which of the following compounds is a carboxylic acid?