Q: A sample contains 70% $^{35}\mathrm{Cl}$ (mass = 34.97 u) and 30% $^{37}\mathrm{Cl}$ (mass = 36.97 u). What is the average atomic mass of chlorine?

$(0.70 \times 34.97) + (0.30 \times 36.97) = 35.57\ \mathrm{u}$

Q: A student converts 5.0 miles to kilometers using the conversion factor $1\ \mathrm{mile} = 1609.34\ \mathrm{m}$ and $1\ \mathrm{km} = 1000\ \mathrm{m}$. What is the correct answer?

$5.0\ \mathrm{miles} \times \frac{1609.34\ \mathrm{m}}{1\ \mathrm{mile}} \times \frac{1\ \mathrm{km}}{1000\ \mathrm{m}} = 8.0\ \mathrm{km}$

Question 1

Which of the following best describes the difference between a compound and a mixture?

Accepted Answer

A compound has a fixed composition with elements chemically bonded, while a mixture consists of substances physically combined in variable proportions.

Question 2

Which of the following is a chemical change?

Accepted Answer

Burning of gasoline in an engine

Question 3

A student measures the mass of a metal sample as 15.0 g and its volume as 2.5 mL. What is the density of the metal, and how many significant figures should the answer have?

Accepted Answer

$d = \frac{15.0\ \mathrm{g}}{2.5\ \mathrm{mL}} = 6.0\ \mathrm{g/mL}$, 2 significant figures

Question 4

Convert 25.0 °C to Kelvin.

Accepted Answer

$K = 25.0 + 273.15 = 298.15\ \mathrm{K}$

Question 5

Which of the following is a homogeneous mixture?

Accepted Answer

Salt water

Question 6

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 7

Which element is a metalloid according to the periodic table provided?

Accepted Answer

Silicon (Si)

Question 8

A sample contains 70% $^{35}\mathrm{Cl}$ (mass = 34.97 u) and 30% $^{37}\mathrm{Cl}$ (mass = 36.97 u). What is the average atomic mass of chlorine?

Accepted Answer

$(0.70 	imes 34.97) + (0.30 	imes 36.97) = 35.57\ \mathrm{u}$

Question 9

Which of the following ions is most likely formed by magnesium?

Accepted Answer

$\mathrm{Mg}^{2+}$

Question 10

Which of the following compounds is ionic?

Accepted Answer

$\mathrm{NaCl}$

Question 11

What is the empirical formula for glucose ($\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$)?

Accepted Answer

$\mathrm{CH}_2\mathrm{O}$

Question 12

Which of the following is the correct name for $\mathrm{FeCl}_3$?

Accepted Answer

Iron(III) chloride

Question 13

A student converts 5.0 miles to kilometers using the conversion factor $1\ \mathrm{mile} = 1609.34\ \mathrm{m}$ and $1\ \mathrm{km} = 1000\ \mathrm{m}$. What is the correct answer?

Accepted Answer

$5.0\ \mathrm{miles} 	imes \frac{1609.34\ \mathrm{m}}{1\ \mathrm{mile}} 	imes \frac{1\ \mathrm{km}}{1000\ \mathrm{m}} = 8.0\ \mathrm{km}$

Question 14

Which of the following statements about the Rutherford gold foil experiment is correct?

Accepted Answer

It demonstrated that atoms have a small, dense, positively charged nucleus.

Question 15

Which of the following is the correct chemical symbol for an atom with 17 protons, 18 neutrons, and 17 electrons?

Accepted Answer

$^{35}\mathrm{Cl}$

Question 16

Which of the following is a physical property?

Accepted Answer

Boiling point

Question 17

Which of the following best describes the difference between accuracy and precision?

Accepted Answer

Accuracy refers to how close a measurement is to the true value, while precision refers to how close repeated measurements are to each other.

Question 18

Which group on the periodic table contains the noble gases?

Accepted Answer

Group 8A (18)

Question 19

Which of the following is the correct formula for the compound formed between aluminum and oxygen?

Accepted Answer

$\mathrm{Al}_2\mathrm{O}_3$

Question 20

How many significant figures are in the measurement 0.00450 g?

Accepted Answer

3

General Chemistry Study Guide: Chapters 1 & 2

Study Guide - Practice Questions

Study Guide - Flashcards