$$\mathrm{FC} = \text{valence electrons} - \frac{1}{2}(\text{bonding electrons}) - \text{lone pair electrons}$$

Question 1

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

Accepted Answer

In a polar covalent bond, electrons are shared unequally between atoms, while in an ionic bond, electrons are transferred from one atom to another.

Question 2

Given the electronegativities $$\mathrm{C} = 2.5$$ and $$\mathrm{O} = 3.4$$, what type of bond is present in a $$\mathrm{C}-\mathrm{O}$$ bond?

Accepted Answer

Polar covalent

Question 3

What is the formal charge on the oxygen atom in methanol ($$\mathrm{CH_3OH}$$)?

Accepted Answer

$$0$$

Question 4

Which formula correctly calculates the formal charge ($$\mathrm{FC}) on an $$atom in a Lewis structure?

Accepted Answer

$$\mathrm{FC} = 	ext{valence electrons} - \frac{1}{2}(	ext{bonding electrons}) - 	ext{lone pair electrons}$$

Question 5

Which of the following molecules contains both ionic and covalent bonds?

Accepted Answer

$$\mathrm{CH_3COONa}$$

Question 6

What is the bond angle in a molecule with $$\mathrm{sp^3$}$$ hybridized central atom, such as methane ($$\mathrm{CH_4$}$$)?

Accepted Answer

$$109.5^\circ$$

Question 7

Which statement about sigma ($$\sigma) $$and pi ($$\pi) $$bonds is correct?

Accepted Answer

A double bond consists of one $$\sigma$$ bond and one $$\pi$$ bond.

Question 8

Which hybridization is expected for the central carbon atom in ethyne ($$\mathrm{C_2H_2}$$)?

Accepted Answer

$$\mathrm{sp}$$

Question 9

What is the main reason for the geometry of molecules as explained by VSEPR theory?

Accepted Answer

Electron pairs repel each other, arranging themselves as far apart as possible.

Question 10

Which of the following best describes the difference between bonding and antibonding molecular orbitals?

Accepted Answer

Bonding orbitals result from constructive interference of atomic orbitals, while antibonding orbitals result from destructive interference.

Question 11

Which of the following statements about free rotation around bonds is correct?

Accepted Answer

Free rotation is possible around single ($$\sigma) $$bonds but restricted around double ($$\pi) $$bonds.

Question 12

A molecule has a central atom with $$\mathrm{sp^2$}$$ hybridization. What is the expected bond angle?

Accepted Answer

$$120^\circ$$

Question 13

Which of the following best explains why saturated fats have different physical properties than unsaturated fats?

Accepted Answer

Unsaturated fats contain double bonds, introducing kinks that prevent tight packing.

Question 14

Which of the following molecules is most likely to have a linear geometry?

Accepted Answer

$$\mathrm{C_2H_2}$$

Question 15

If the difference in electronegativity ($$\Delta EN) $$between two atoms is $$3.0$$, what type of bond is most likely formed?

Accepted Answer

Ionic

Question 16

Which of the following is a correct statement about the phases of atomic orbitals?

Accepted Answer

Phases in atomic orbitals are related to the sign (+ or -) of the wave function, affecting constructive or destructive interference.

Question 17

Which of the following best describes the hybridization of the carbon atom in formaldehyde ($$\mathrm{CH_2O}$$)?

Accepted Answer

$$\mathrm{sp^2$}$$

Question 18

Which of the following is true about the electron density in a $$\mathrm{C-F}$$ bond?

Accepted Answer

Electron density is greater around F due to its higher electronegativity.

Question 19

Which of the following molecules would you expect to have a trigonal planar geometry?

Accepted Answer

$$\mathrm{CH_2O}$$

Lecture 2 Part 2 Properties of Atoms & Bonds – CHEM 2311 Organic Chemistry I (Lecture 2 Study Notes)

Study Guide - Practice Questions