Question 1

Which of the following best describes the difference between a polar covalent bond and a nonpolar covalent bond?

Accepted Answer

A polar covalent bond involves the unequal sharing of electrons due to a difference in electronegativity between the atoms.

Question 2

Given the following electronegativity values: $$\mathrm{H} = 2.1$$, $$\mathrm{Cl} = 3.0$$, classify the bond in $$\mathrm{HCl}.$$

Accepted Answer

Polar covalent

Question 3

Which of the following molecules has a linear molecular geometry?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 4

What is the formal charge on the oxygen atom in the hydroxide ion ($$\mathrm{OH^-}$$)?

Accepted Answer

$$-1$$

Question 5

Which of the following statements about resonance structures is correct?

Accepted Answer

Resonance structures represent different possible distributions of electrons, not atoms.

Question 6

Which of the following molecules is expected to have a bond angle closest to $$109.5^\circ$$?

Accepted Answer

$$\mathrm{NH_3$}$$

Question 7

What is the electron configuration for silicon ($$\mathrm{Si}$$)?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$ $$3s^2$$ $$3p^2$$

Question 8

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

Accepted Answer

The molecule has a bent geometry and a significant difference in electronegativity between O and H.

Question 9

Which of the following is the correct Lewis dot structure for carbon?

Accepted Answer

A symbol C surrounded by 4 dots.

Question 10

Which of the following molecules contains a triple bond?

Accepted Answer

$$\mathrm{C_2H_2}$$

Question 11

What is the hybridization of the central atom in $$\mathrm{BF_3$}$$?

Accepted Answer

$$sp^2$$

Question 12

Which of the following best describes the shape and bond angle of $$\mathrm{CH_4$}$$?

Accepted Answer

Tetrahedral, $$109.5^\circ$$

Question 13

Which of the following is a correct statement about formal charge?

Accepted Answer

Formal charge is the number of valence electrons minus all unshared electrons and half of all shared electrons.

Question 14

Which of the following molecules is nonpolar despite having polar bonds?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 15

Which of the following is the correct condensed structural formula for ethanol?

Accepted Answer

$$\mathrm{CH_3CH_2OH}$$

Question 16

Which of the following is a secondary amine?

Accepted Answer

$$\mathrm{(CH_3$)_2NH}$$

Question 17

Which of the following is the correct formula for a carboxylic acid functional group?

Accepted Answer

$$\mathrm{-COOH}$$

Question 18

Which of the following statements about VSEPR theory is correct?

Accepted Answer

VSEPR theory predicts the arrangement of atoms based on minimizing the repulsion between electron pairs.

Question 19

Which of the following molecules has a trigonal planar geometry?

Accepted Answer

$$\mathrm{BF_3$}$$

Question 20

Which of the following is a correct statement about the rules for writing resonance structures?

Accepted Answer

All resonance structures must have the same number of valence electrons.

Covalent Bonding and Shapes of Molecules: Structured Study Notes

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