Chem bonding quiz

Rank the following compounds from the highest boiling point to the lowest boiling point: Water, oxygen, diamond, hydrogen chloride (HCl)

• Diamond, water, hydrogen chloride, oxygen

• Diamond, hydrogen chloride, oxygen, water

• Water, oxygen, diamond, hydrogen chloride

• Oxygen, water, hydrogen chloride, diamond

Answer explanation

Diamond is a giant crystal structure where carbon atoms are bonded by strong covalent bonds

Hydrogen chloride can form dipole-dipole attraction due to the polar H-Cl bond, but water can form hydrogen bonds in addition to dipole-dipole bonds due to the presence of a hydrogen atom directly attached to an oxygen atom, and a lone pair on the oxygen atom

Oxygen molecule cannot form dipole-dipole attraction due to the lack of polar bonds, and can only form weaker LDF forces

What are the conditions required for hydrogen bonding?

• 1. 1. Hydrogen atoms attached to any atoms

  2. 2. Presence of water

• 1. 1. Hydrogen atoms attached to any atoms

  2. 2. Absence of water

• 1. 1. Hydrogen atoms attached to N, O or F atom

  2. 2. Presence of lone pair of electron on N, O or F

• 1. 1. Hydrogen atoms attached to N, O or F atom

  2. 2. Presence of lone pair of electron on any atom

Double bonds consist of

• A sigma bond

• A sigma bond and a delta bond

• A pi bond only

• Sigma bond and pi bond

What is the hybridization scheme of the central sulfur atom?

• sp2

• sp

• sp3

• sp3d1

Answer explanation

There are three electron domains around the sulfur atom --> Two bond pairs and one lone pair

What molecular geometry does this molecule have?

• Tetrahedral

• Bent

• Trigonal pyramidal

• Trigonal planar

Why does a benzene ring have higher stability than 1,3,5 - cyclohexatriene?

• All the bonds in benzene are single bonds, while 1,3,5-cyclohexatriene has double bonds

• Benzene has a delocalized electron conjugated system, and 1,3,5-cyclohexatriene doesn't

• Benzene takes less energy to form than 1,3,5-cyclohexatriene

• None of the above

Which of these resonance structures are the most stable?

• 1

• 2

• 3

What is the formal charge on the right oxygen atom?

• 0

• +1

• -1

• +2

What is the bond angle between each B-H bond in this molecule?

• 90 degrees

• 180 degrees

• 120 degrees

• 360 degrees

How many sigma bonds are in this molecule?

• 5

• 6

• 7

• 8