Inter and Intramolecular forces

Front

Which of the following has hydrogen bonding? Options: CBr₄, NO₂, H₂S, NH₃

Back

NH₃

Answer explanation

Hydrogen bonding occurs when hydrogen is bonded to N, O, or F. Among the options, NH3 (ammonia) has hydrogen bonded to nitrogen, allowing for hydrogen bonding. CBr4, NO2, and H2S do not exhibit this type of bonding.

Front

Rank these in order of strength of the attraction: covalent bond, hydrogen bond, dipole-dipole attraction.

Back

covalent bond > hydrogen bond > dipole-dipole

Answer explanation

Covalent bonds are the strongest due to shared electrons, followed by hydrogen bonds which are weaker attractions between polar molecules. Dipole-dipole attractions are the weakest, occurring between molecules with permanent dipoles.

Front

Type of intermolecular force responsible for the attraction pictured above.

Back

Hydrogen Bonds

Answer explanation

Hydrogen bonds are a specific type of dipole-dipole interaction that occur when hydrogen is bonded to highly electronegative atoms like oxygen or nitrogen, leading to strong attractions between molecules.

Front

Intermolecular forces are attractions between ______.

Back

Neighboring molecules

Answer explanation

Intermolecular forces are attractions between neighboring molecules, which allow them to interact and influence each other's properties. This distinguishes them from forces within a molecule or between charged particles.

Front

What kind of force is the arrow pointing to?

Back

Intermolecular Force

Answer explanation

The arrow points to an Intermolecular Force, which is the attraction between molecules. Intramolecular Forces occur within a molecule, while Intermolecular Forces are responsible for interactions between different molecules.

Front

Does CH₄ have hydrogen bonding? Note, the electronegativity of H is 2.1 and C is 2.5.

Back

no

Answer explanation

CH4 (methane) does not exhibit hydrogen bonding because the electronegativity difference between C (2.5) and H (2.1) is too small to create the strong dipole necessary for hydrogen bonds. Therefore, the answer is no.

Front

In CF₄, which charge will the Fluorine atoms tend to have given that fluorine has an electronegativity of 3.0 and carbon has an electronegativity of 2.5?

Back

slight negative

Answer explanation

In CF4, fluorine (3.0) is more electronegative than carbon (2.5), leading to an uneven sharing of electrons. This results in fluorine atoms acquiring a slight negative charge due to their stronger attraction for the bonding electrons.

Front

This is an example of a(n) __________.

Back

Dipole

Answer explanation

A dipole occurs when there is a separation of charge within a molecule, leading to positive and negative ends. This is a key characteristic of polar molecules, making 'Dipole' the correct choice in this context.

Front

Correct Lewis dot structure for fluorine (F₂)? Options: A, B, C, D

Back

B

Answer explanation

The correct Lewis dot structure for F2 (fluorine molecule) is choice B, which shows two fluorine atoms sharing a pair of electrons, represented by a single bond, and each atom has three lone pairs of electrons.

Front

Which is the correct structure for ammonia? (Top picture is A, bottom picture is D.) Options: A, B, C, D.

Back

Option C

Answer explanation

Ammonia (NH3) has a trigonal pyramidal structure with a nitrogen atom bonded to three hydrogen atoms and a lone pair of electrons. Option C correctly represents this geometry, while the other options do not.