Question 1

Which of the following best explains why carbon is the central element in organic chemistry?

Accepted Answer

Carbon can form up to four covalent bonds, allowing for a variety of stable structures.

Question 2

Which of the following electronic configurations represents the ground state of a neutral nitrogen atom?

Accepted Answer

$$1s^22s^22$p^3$$

Question 3

A molecule of ethylene ($$C_2H_4) $$contains which combination of bonds between the two carbon atoms?

Accepted Answer

One sigma bond and one pi bond

Question 4

Which of the following statements about resonance structures is correct?

Accepted Answer

The true structure of a molecule is a hybrid of all possible resonance forms.

Question 5

Given the empirical formula $$CH_2$$ and a molecular weight of $$56.11\ \mathrm{g/mol}$$, what is the molecular formula?

Accepted Answer

$$C_4H_8$$

Question 6

Which of the following best describes the bonding in the acetate ion ($$CH_3CO_2^-) $$after deprotonation of acetic acid?

Accepted Answer

The negative charge is delocalized equally over both oxygen atoms due to resonance.

Question 7

Which of the following molecules contains an ionic bond?

Accepted Answer

NaBr

Question 8

What is the formal charge on the carbon atom in the methyl anion ($$CH_3$$^-$$)?

Accepted Answer

$$-1$$

Question 9

Which of the following best describes the hybridization and geometry of the carbon atom in methane ($$CH_4$$)?

Accepted Answer

sp$$^3$$ hybridization, tetrahedral geometry

Question 10

Which of the following is a constitutional isomer of dimethyl ether ($$CH_3OCH_3$$)?

Accepted Answer

Ethanol ($$CH_3CH_2OH)$$

Question 11

Which of the following statements about the 2p atomic orbitals is correct?

Accepted Answer

There are three 2p orbitals, each oriented at right angles to each other.

Question 12

Which of the following best describes the change in electronegativity across the periodic table?

Accepted Answer

Electronegativity increases from left to right and from bottom to top.

Question 13

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

Accepted Answer

A pi bond results from the sideways overlap of two parallel p orbitals.

Question 14

How many sigma ($$\sigma) $$and pi ($$\pi) $$bonds are present in a molecule of acetylene ($$C_2H_2$$)?

Accepted Answer

3 sigma bonds and 2 pi bonds

Question 15

Which of the following is the correct order of decreasing electronegativity for the atoms F, O, Br, and C?

Accepted Answer

F \u003e O \u003e Br \u003e C

Question 16

Which of the following best describes the molecular geometry and bond angle of formaldehyde ($$H_2CO$$)?

Accepted Answer

Trigonal planar, $$120^\circ$$

Question 17

Which of the following statements about single and double bonds is correct?

Accepted Answer

Single bonds can freely rotate, but double bonds cannot due to the presence of a pi bond.

Question 18

Which of the following is a major contributor to resonance stabilization in the acetate ion?

Accepted Answer

Both oxygen atoms have complete octets and share the negative charge.

Question 19

Which of the following best describes the hybridization of the nitrogen atom in ammonia ($$NH_3$$)?

Accepted Answer

sp$$^3$$ hybridization with a tetrahedral electron geometry

Structure and Bonding in Organic Chemistry: Chapter 1 Study Notes

Study Guide - Practice Questions