$$\frac{2.00}{2.00 + 16.00} \times 100 = 11.1\%$$

$$12.01 + 2 \times 16.00 = 44.01\ \mathrm{g/mol}$$

$$1.06 \times 250 = 265\ \mathrm{g}$$

Question 1

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

Accepted Answer

A homogeneous mixture has a uniform composition throughout, while a heterogeneous mixture does not.

Question 2

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

Accepted Answer

$$\mathrm{SO_4$^{2-}}$$

Question 3

A sample of a compound contains 2.00 g of hydrogen and 16.00 g of oxygen. What is the percent by mass of hydrogen in the compound?

Accepted Answer

$$\frac{2.00}{2.00 + 16.00} 	imes 100 = 11.1\%$$

Question 4

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 5

Which of the following ions is correctly paired with its name?

Accepted Answer

$$\mathrm{NO_3$^-}$$, Nitrate

Question 6

How many protons, neutrons, and electrons are in $$^{37}_{17}\mathrm{Cl}$$?

Accepted Answer

17 protons, 20 neutrons, 17 electrons

Question 7

Which of the following best describes the octet rule?

Accepted Answer

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

Question 8

What is the molar mass of $$\mathrm{CO_2$}$$?

Accepted Answer

$$12.01 + 2 	imes 16.00 = 44.01\ \mathrm{g/mol}$$

Question 9

Which of the following compounds is ionic?

Accepted Answer

$$\mathrm{NaCl}$$

Question 10

A patient’s blood sample has a density of $$1.06\ \mathrm{g/mL}. $$What is the mass of $$250\ \mathrm{mL} of $$blood?

Accepted Answer

$$1.06 	imes 250 = 265\ \mathrm{g}$$

Question 11

Which of the following is the correct Lewis structure for methane ($$\mathrm{CH_4$}$$)?

Accepted Answer

A central C atom with four single bonds to four H atoms.

Question 12

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

Accepted Answer

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

Question 13

Which of the following ions is polyatomic?

Accepted Answer

$$\mathrm{NH_4$^+}$$

Question 14

What is the correct name for $$\mathrm{K_2SO_4}$$?

Accepted Answer

Potassium sulfate

Question 15

Which of the following best describes the penetrating power of gamma radiation compared to alpha and beta radiation?

Accepted Answer

Gamma radiation has greater penetrating power than both alpha and beta radiation.

Question 16

How many moles are in $$18.0\ \mathrm{g} of $$water ($$\mathrm{H_2O}$$)? (Molar mass of $$\mathrm{H_2O} is$$ $$18.0\ \mathrm{g/mol})$$

Accepted Answer

$$\frac{18.0}{18.0} = 1.00$$ mole

Question 17

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

Accepted Answer

$$\mathrm{PO_4$^{3-}}$$

Question 18

Which of the following molecules is nonpolar?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 19

Convert $$25.0\ ^\circ\mathrm{C} to $$Fahrenheit using the equation $$F = \frac{9}{5}C + 32.$$

Accepted Answer

$$F = \frac{9}{5} 	imes 25.0 + 32 = 77.0\ ^\circ\mathrm{F}$$

CHEM 102 Test 1 Study Guide: Chapters 1–3 (Matter, Atoms, Compounds)

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