$$40.08 + 2 \times (14.01 + 3 \times 16.00) = 164.10 g/$$mol

2.4 mol $$\times 12 = 28.8 $$mol

Question 1

Which of the following best explains why ionic bonds form between metals and nonmetals?

Accepted Answer

Metals tend to lose electrons and nonmetals tend to gain electrons, resulting in electron transfer and the formation of oppositely charged ions.

Question 2

Which of the following compounds is classified as a molecular compound?

Accepted Answer

CO$$_2$$

Question 3

What is the empirical formula for a compound with the molecular formula C$$_6H$_{12}O$_6$$?

Accepted Answer

CH$$_2O$$

Question 4

How many oxygen atoms are present in one formula unit of Ca(NO$$_3$$)$$_2$$?

Accepted Answer

6

Question 5

Which of the following Lewis symbols correctly represents a chloride ion (Cl$$^-$$)?

Accepted Answer

$$\cdot \cdot \cdot \cdot \cdot \cdot \cdot \cdotCl$^-$$

Question 6

Which of the following best describes lattice energy ($$U) in an $$ionic compound?

Accepted Answer

The energy released when one mole of an ionic compound forms from its free ions in the gas phase.

Question 7

Given the lattice energy equation $$U = k \frac{Q_1$ Q_2$}{d}$$, which change would result in a higher (more exothermic) lattice energy?

Accepted Answer

Decreasing the distance $$d$$ between ions.

Question 8

Which of the following is the correct formula for the ionic compound formed between calcium and phosphate?

Accepted Answer

Ca$$_3(PO$_4$$)$$_2$$

Question 9

What is the name of the compound FeCl$$_3$$?

Accepted Answer

Iron(III) chloride

Question 10

Calculate the formula mass of Ca(NO$$_3$$)$$_2 ($$atomic masses: Ca = 40.08, N = 14.01, O = 16.00).

Accepted Answer

$$40.08 + 2 	imes (14.01 + 3 	imes 16.00) = 164.10 g/$$mol

Question 11

A sample contains 72.5 g of CCl$$_4 ($$molar mass = 153.82 g/mol). How many moles are present?

Accepted Answer

$$\frac{72.5}{153.82} = 0.471$$ mol

Question 12

Which of the following best explains why the lattice energy of BaO is much more exothermic than that of CsF?

Accepted Answer

Ba$$^{2+}$$ and O$$^{2-}$$ have higher charges than Cs$$^+$$ and F$$^-$$, leading to stronger electrostatic attraction.

Question 13

Which of the following is the correct name for the molecular compound SO$$_3$$?

Accepted Answer

Sulfur trioxide

Question 14

How many moles of hydrogen atoms are present in 2.4 mol of C$$_6H$_{12}$$?

Accepted Answer

2.4 mol $$	imes 12 = 28.8 $$mol

Question 15

Which of the following is the correct formula for potassium hydrogen carbonate?

Accepted Answer

KHCO$$_3$$

Question 16

A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is its empirical formula?

Accepted Answer

CH$$_2O$$

Question 17

Which of the following is a correct Lewis structure for a molecule of nitrogen gas (N$$_2$$)?

Accepted Answer

:N≡N:

Question 18

Which of the following best describes the difference between ionic and molecular compounds?

Accepted Answer

Ionic compounds are formed by transferring electrons, while molecular compounds are formed by sharing electrons.

Question 19

Which of the following is the correct name for the compound CuSO$$_4$$·5H$$_2O$$?

Accepted Answer

Copper(II) sulfate pentahydrate

Chapter 4: Compounds, Chemical Formulas, and Composition

Study Guide - Practice Questions