Question 1

Which of the following statements best describes the trend of electronegativity across the periodic table?

Accepted Answer

Electronegativity increases from left to right across a period and decreases from top to bottom in a group.

Question 2

Given the electronegativity values: $$\mathrm{H} = 2.1$$, $$\mathrm{Cl} = 3.0$$, what type of bond is formed between hydrogen and chlorine?

Accepted Answer

Polar covalent

Question 3

Which of the following molecules is nonpolar, despite containing polar bonds?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 4

What is the molecular shape of ammonia ($$\mathrm{NH_3$}) $$according to VSEPR theory?

Accepted Answer

Trigonal pyramidal

Question 5

Which of the following intermolecular forces is the strongest?

Accepted Answer

Ionic bonds

Question 6

A molecule of methane ($$\mathrm{CH_4$}) $$has which of the following shapes and bond angles?

Accepted Answer

Tetrahedral, $$109^\circ$$

Question 7

Which of the following best explains why water ($$\mathrm{H_2O}) is a $$polar molecule?

Accepted Answer

It has polar bonds and a bent shape, so the dipoles do not cancel.

Question 8

Which of the following compounds would have the highest melting point?

Accepted Answer

$$\mathrm{NaCl} ($$ionic bonds)

Question 9

What is the main type of attractive force present in liquid $$\mathrm{Cl_2$}$$?

Accepted Answer

Dispersion forces

Question 10

Which of the following statements about hydrogen bonding is correct?

Accepted Answer

Hydrogen bonds occur when hydrogen is bonded to F, O, or N and interacts with a lone pair on F, O, or N.

Question 11

Which of the following molecules has a trigonal planar shape?

Accepted Answer

$$\mathrm{CH_2O} ($$formaldehyde)

Question 12

A bond between sodium ($$\mathrm{Na}$$, electronegativity 0.9) and chlorine ($$\mathrm{Cl}$$, electronegativity 3.0) is best classified as:

Accepted Answer

Ionic

Question 13

Which of the following best describes the electron geometry and molecular shape of $$\mathrm{SO_2$}$$?

Accepted Answer

Trigonal planar electron geometry, bent molecular shape

Question 14

Which of the following molecules is expected to have the lowest boiling point?

Accepted Answer

$$\mathrm{CO_2$} ($$dispersion forces)

Question 15

Which of the following is a correct statement about dipole–dipole attractions?

Accepted Answer

They occur between the positive end of one polar molecule and the negative end of another.

Question 16

A molecule with four electron groups around the central atom, two of which are lone pairs, will have which molecular shape?

Accepted Answer

Bent

Question 17

Which of the following best explains why $$\mathrm{$$CCl_4$$} is $$nonpolar?

Accepted Answer

It has polar bonds, but the molecular geometry causes the dipoles to cancel.

Question 18

Which of the following is the correct order of increasing strength of attractive forces between molecules?

Accepted Answer

Dispersion forces \u003c Dipole–dipole \u003c Hydrogen bonds \u003c Ionic bonds

Question 19

Which of the following best describes the bonding in $$\mathrm{HCl}$$?

Accepted Answer

Polar covalent bond with unequal sharing of electrons

Question 20

Which of the following molecules is polar due to its molecular geometry, even though all the bonds are identical?

Accepted Answer

$$\mathrm{NH_3$}$$

Ionic and Molecular Compounds: Electronegativity, Bond Polarity, Molecular Shapes, and Intermolecular Forces

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