Bonding

Question 1

When does the ionic bond form?

Answer 1

The ionic bond forms when electrons transfer completely from one atom to another, resulting in oppositely charge species that attract each other via electrostatic interaction.

Question 2

For ionic bonds, is electrostatic energy positive or negative?

Answer 2

Electrostatic energy is negative because q1 and q2 are opposite in charge (If q1 and q2 are not opposite in charge, then they would repel each other, and no ionic bond would form).

Question 3

If the magnitude of the electrostatic potential is great, how is that reflected in the strength of the ionic bond?

Answer 3

The greater the magnitude of electrostatic potential, the stronger the ionic bond.

Question 4

Which is stronger–gravitational force or electrostatic force?

Answer 4

The big difference is that G is tiny compared to k, because gravitational force is weaker compared to the much stronger electrostatic force.

Question 5

When does a covalent bond arise?

Answer 5

The covalent bond results when there is a sharing of electrons between two atoms, resulting in the overlap of their electron orbitals.

Question 6

What are σ bonds?

Answer 6

σ bonds are single bonds. They also make up the first bond of double and triple bonds.

Question 7

What are π bonds?

Answer 7

bonds are double and triple bonds. They make up the second bond in a double bond, and both the second and the third bond in a triple bond.

Question 8

Draw the hybridizations of a carbon atom.

Question 9

With a VSEPR # of 2, what molecular geometries are possible?

Answer 9

Question 10

With a VSEPR # of 3, what molecular geometries are possible?

Answer 10

Question 11

With a VSEPR # of 4, what molecular geometries are possible?

Answer 11

Question 12

With a VSEPR # of 5, what molecular geometries are possible?

Answer 12

Question 13

With a VSEPR # of 6, what molecular geometries are possible?

Answer 13

Question 14

What are “nature’s three rules?”

Answer 14

1. Octet rule is satisfied in every atom (except for boron group and hydrogen).
2. No formal charges.
3. If there must be formal charges, like charges are apart and unlike charges are close together.

Question 15

How do you calculate formal charge?

Answer 15

Where V is the number of valence electrons of the atom in isolation (atom in ground state); N is the number of non-bonding valence electrons on this atom in the molecule; and B is the total number of electrons shared in covalent bonds with other atoms in the molecule. There are two electrons shared per single covalent bond.

Question 16

Calculate formal charge the single bonded oxygen of NO₂^-

Answer 16

FC = 6 - 6 - (2÷2) = -1

Question 17

Distinguish between Lewis acids and Lewis bases.

Answer 17

• Lewis acid accept electron pairs. They don’t have lone pairs on the central atom. eg. BF₃
• Lewis bases donate electron pairs. They have lone pairs on their central atom. eg. NH₃

Question 18

Does the more electronegative atom receive the more negative or more positive partial charge?

Answer 18

• The more electronegative atom receives a partial negative charge.
• The less electronegative atom receives a partial positive charge.

Question 19

Dipole movements depend on:

Answer 19

• The greater electronegativity difference, the greater the charge and hence the dipole moment.
• The greater the distance separating the charges, the greater the dipole moment.

Question 20

What types of molecules do not have dipole movements?

Answer 20

• Molecules with symmetrical partial charge distribution do not have dipole moments. eg. CCl₄ do not have a dipole moment because the partially negative chlorine atoms are arranged symmetrically in a tetrahedron.
• The symmetry cancels out their individual dipole moments.
• Things with a dipole moment are said to be polar.