Question 1

Which statement best describes the formation of an ionic bond between sodium and chlorine?

Accepted Answer

Sodium transfers an electron to chlorine, resulting in oppositely charged ions held together by electrostatic attraction.

Question 2

Which factor increases the lattice energy of an ionic compound?

Accepted Answer

Increasing the charge of the ions.

Question 3

Why does NaCl have a higher melting point than KCl?

Accepted Answer

NaCl has smaller ions, resulting in stronger electrostatic attraction and higher lattice energy.

Question 4

According to the electron-sea model, which property of metals is explained by the presence of delocalized electrons?

Accepted Answer

Good electrical conductivity.

Question 5

Which statement about band theory and electrical conductivity is correct?

Accepted Answer

Metals have overlapping valence and conduction bands, allowing electrons to move freely.

Question 6

Which molecule is an example of a coordinate (dative covalent) bond?

Accepted Answer

Ammonium ion, $$NH_4$$^+$$

Question 7

Which of the following is an exception to the octet rule due to having fewer than eight electrons around the central atom?

Accepted Answer

Boron trifluoride, $$BF_3$$

Question 8

How many bonding pairs and lone pairs are present in a water molecule ($$H_2O$$)?

Accepted Answer

2 bonding pairs, 2 lone pairs

Question 9

Which statement about resonance structures is correct?

Accepted Answer

Resonance structures differ only in the location of electrons, not atoms.

Question 10

What is the formal charge on the oxygen atom in the most stable Lewis structure of $$CO_2$$?

Accepted Answer

$$0$$

Question 11

Which molecule is non-polar despite having polar bonds?

Accepted Answer

Carbon dioxide, $$CO_2$$

Question 12

Which intermolecular force is the strongest?

Accepted Answer

Hydrogen bonding

Question 13

Which of the following molecules can form hydrogen bonds with water?

Accepted Answer

Methanol, $$CH_3OH$$

Question 14

Which statement best explains why ionic compounds conduct electricity in molten or aqueous state but not in solid state?

Accepted Answer

Ions are fixed in place in the solid state and cannot move to conduct electricity.

Question 15

Which type of hybridization is present in the central atom of methane ($$CH_4$$)?

Accepted Answer

$$sp^3$$

Question 16

Which factor causes the boiling point of alcohols to be higher than that of alkanes of similar molecular mass?

Accepted Answer

Alcohols have hydrogen bonding, which is stronger than the forces in alkanes.

Question 17

Which statement about solubility is correct?

Accepted Answer

Polar solutes dissolve best in polar solvents due to similar intermolecular forces.

Question 18

Which of the following molecules has a trigonal planar shape according to VSEPR theory?

Accepted Answer

Boron trifluoride, $$BF_3$$

Question 19

Which of the following best describes a pi ($$\pi) $$bond?

Accepted Answer

A bond formed by sideways overlap of p orbitals.

Question 20

Which of the following molecules will have the largest bond angle?

Accepted Answer

Methane, $$CH_4$$

Molecules and Molecular Structure: Chemical Bonding and Properties

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