Question 1

Which of the following best describes the difference between a formal charge and an oxidation state in organic molecules?

Accepted Answer

Formal charge assigns electrons in bonds equally, while oxidation state assigns all bonding electrons to the more electronegative atom.

Question 2

Given the molecule $$\mathrm{CH_3COOH} ($$acetic acid), what is the formal charge on the oxygen atom in the hydroxyl group?

Accepted Answer

$$0$$

Question 3

Which of the following is the correct Lewis structure for carbon dioxide ($$\mathrm{CO_2$}$$)?

Accepted Answer

O=C=O, with each oxygen having two lone pairs.

Question 4

A student draws the resonance structures for the acetate ion ($$\mathrm{CH_3COO^-}). $$Which statement is correct regarding the resonance?

Accepted Answer

The negative charge is delocalized over both oxygen atoms in the resonance hybrid.

Question 5

Which of the following molecules contains a heteroatom?

Accepted Answer

$$\mathrm{CH_3NH_2} ($$methylamine)

Question 6

Which of the following is the correct order of electronegativity for the atoms: O, N, C, H?

Accepted Answer

O \u003e N \u003e C \u003e H

Question 7

A molecule has the formula $$\mathrm{C_3H_7NO_2}. $$Which functional group is most likely present?

Accepted Answer

Carboxylic acid

Question 8

Which of the following statements about resonance structures is TRUE?

Accepted Answer

The actual molecule is a hybrid of all valid resonance structures.

Question 9

What is the hybridization of the central carbon atom in formaldehyde ($$\mathrm{CH_2O}$$)?

Accepted Answer

$$sp^2$$

Question 10

Which of the following best explains why water ($$\mathrm{H_2O}) $$has a bent molecular geometry?

Accepted Answer

The two lone pairs on oxygen repel the bonding pairs, resulting in a bent shape.

Question 11

Which of the following is NOT a valid resonance structure for the nitrate ion ($$\mathrm{NO_3$^-}$$)?

Accepted Answer

A structure with three single bonds to oxygen and the negative charge spread over all three oxygens.

Question 12

Which of the following best describes the difference between a constitutional isomer and a resonance structure?

Accepted Answer

Constitutional isomers are different compounds, resonance structures are different representations of the same compound.

Question 13

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

Accepted Answer

$$\mathrm{CH_3CH_2OH} ($$ethanol)

Question 14

A student is asked to draw the Lewis structure for $$\mathrm{NH_4$^+} ($$ammonium ion). What is the formal charge on the nitrogen atom?

Accepted Answer

$$0$$

Question 15

Which of the following is the correct electron configuration for a neutral carbon atom?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^2$$

Question 16

Which of the following best explains why nitrogen in ammonia ($$\mathrm{NH_3$}) is$$ $$sp^3$$ hybridized?

Accepted Answer

Nitrogen forms three sigma bonds and has one lone pair, requiring four hybrid orbitals.

Question 17

Which of the following is a correct statement about the octet rule in organic chemistry?

Accepted Answer

Atoms like hydrogen and boron are exceptions to the octet rule.

Question 18

Which of the following best describes the geometry around the central atom in $$\mathrm{BF_3$} ($$boron trifluoride)?

Accepted Answer

Trigonal planar

Question 19

Which of the following molecules contains a chiral center?

Accepted Answer

$$\mathrm{CH_3CHBrCH_2CH_3} (2-$$bromobutane)

Organic Chemistry I: Course Schedule and Study Guide (Unit #1A, Klein Ch. 1-2)

Study Guide - Practice Questions