Q: Which of the following is the correct formula for calculating percent composition by mass?

$\text{Percent composition} = \frac{\text{mass of element}}{\text{total mass of compound}} \times 100$

Q: Which of the following is the correct formula for calculating molarity ($M$)?

$M = \frac{\text{moles of solute}}{\text{liters of solution}}$

Q: Which of the following is the correct formula for calculating the number of moles from mass and molar mass?

$\text{moles} = \frac{\text{mass}}{\text{molar mass}}$

Q: Which of the following is the correct formula for calculating dimensional analysis problems involving unit conversion?

$\text{Given unit} \times \frac{\text{Desired unit}}{\text{Given unit}}$

Question 1

Which of the following correctly converts 0.00567 meters to scientific notation?

Accepted Answer

$5.67 	imes 10^{-2}$ m

Question 2

A student measures the mass of a sample as 0.02340 g. How many significant figures are in this measurement?

Accepted Answer

5

Question 3

Which of the following is the correct rearrangement of the density formula $D = \frac{m}{V}$ to solve for mass ($m$)?

Accepted Answer

$m = D 	imes V$

Question 4

A chemical reaction releases 150 kJ of energy. How many calories does this correspond to? ($1 	ext{ cal} = 4.184 	ext{ J}$)

Accepted Answer

35,870 cal

Question 5

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed by the transfer of electrons from one atom to another

Question 6

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

Accepted Answer

$1s^2\ 2s^2\ 2p^4$

Question 7

Which of the following is NOT a type of intermolecular force?

Accepted Answer

Covalent bond

Question 8

A compound contains 40% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is the empirical formula of the compound?

Accepted Answer

$CH_2O$

Question 9

Which of the following statements about polyatomic ions is correct?

Accepted Answer

Polyatomic ions are groups of covalently bonded atoms that carry a net charge.

Question 10

Which of the following is the correct formula for ammonium sulfate?

Accepted Answer

$(NH_4)_2SO_4$

Question 11

A student mixes 50.0 mL of 0.200 M NaCl with 150.0 mL of water. What is the final concentration of NaCl?

Accepted Answer

0.0500 M

Question 12

Which of the following is a correct statement about the periodic table?

Accepted Answer

Elements in the same group have similar chemical properties.

Question 13

Which of the following is the correct formula for calculating percent composition by mass?

Accepted Answer

$	ext{Percent composition} = \frac{	ext{mass of element}}{	ext{total mass of compound}} 	imes 100$

Question 14

Which of the following is a correct Lewis structure for water ($H_2O$)?

Accepted Answer

O atom with two lone pairs and two single bonds to H atoms

Question 15

Which of the following is the correct formula for calculating molarity ($M$)?

Accepted Answer

$M = \frac{	ext{moles of solute}}{	ext{liters of solution}}$

Question 16

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

Accepted Answer

Atoms tend to gain, lose, or share electrons to achieve eight electrons in their valence shell.

Question 17

Which of the following is the correct formula for calculating the number of moles from mass and molar mass?

Accepted Answer

$	ext{moles} = \frac{	ext{mass}}{	ext{molar mass}}$

Question 18

Which of the following is the correct formula for sulfate ion?

Accepted Answer

$SO_4^{2-}$

Question 19

Which of the following is a correct statement about covalent bonds?

Accepted Answer

Covalent bonds involve the sharing of electrons between two nonmetal atoms.

Question 20

Which of the following is the correct formula for calculating dimensional analysis problems involving unit conversion?

Accepted Answer

$	ext{Given unit} 	imes \frac{	ext{Desired unit}}{	ext{Given unit}}$

Chem 100 Study Guide: Units 1-3 Core Concepts

Study Guide - Practice Questions

Study Guide - Flashcards