Q: Which of the following is the correct way to convert $$25.0\ \mathrm{cm} to $$meters using dimensional analysis?

$$25.0\ \mathrm{cm} \times \frac{1\ \mathrm{m}}{100\ \mathrm{cm}} = 0.250\ \mathrm{m}$$

Question 1

Which of the following is an example of a heterogeneous mixture?

Accepted Answer

Salad with lettuce, tomatoes, and cucumbers

Question 2

Which statement best describes a pure substance?

Accepted Answer

A material with a fixed composition and distinct properties

Question 3

Which of the following is a homogeneous mixture?

Accepted Answer

Brass (an alloy of copper and zinc)

Question 4

Which of the following is an example of a chemical change?

Accepted Answer

Burning wood

Question 5

Which of the following best describes an ion?

Accepted Answer

An atom or molecule with a net electric charge due to the loss or gain of electrons

Question 6

Which of the following is a cation?

Accepted Answer

$$\mathrm{Na^+}$$

Question 7

Which of the following is a molecular element?

Accepted Answer

$$\mathrm{O_2$}$$

Question 8

Which of the following is an atomic element?

Accepted Answer

$$\mathrm{He}$$

Question 9

Which of the following best describes a molecular compound?

Accepted Answer

A compound composed of nonmetals bonded together by covalent bonds

Question 10

A student measures the mass of a metal sample as $$12.34\ \mathrm{g}$$ and its volume as $$4.56\ \mathrm{cm^3$}. $$What is the density of the metal, reported with the correct number of significant figures?

Accepted Answer

$$2.7\ \mathrm{g/cm^3$}$$

Question 11

Which of the following is a physical property?

Accepted Answer

Melting point

Question 12

Which of the following best describes the composition of compounds?

Accepted Answer

Compounds are made of two or more elements chemically combined in fixed proportions

Question 13

A solution contains $$5.00\ \mathrm{g} of $$salt dissolved in $$100.0\ \mathrm{g} of $$water. What is the mass percent of salt in the solution?

Accepted Answer

$$4.76\%$$

Question 14

Which of the following is the correct way to convert $$25.0\ \mathrm{cm} to $$meters using dimensional analysis?

Accepted Answer

$$25.0\ \mathrm{cm} 	imes \frac{1\ \mathrm{m}}{100\ \mathrm{cm}} = 0.250\ \mathrm{m}$$

Question 15

A student finds a shiny, silver-colored substance that cannot be separated into simpler substances by physical or chemical means. Which classification best fits this substance?

Accepted Answer

Element

Question 16

Which of the following best describes an anion?

Accepted Answer

A negatively charged ion

Question 17

Which of the following measurements contains the correct number of significant figures?

Accepted Answer

$$0.00450 (3 $$significant figures)

Question 18

A sample of liquid has a mass of $$32.5\ \mathrm{g}$$ and a volume of $$41.2\ \mathrm{mL}. $$What is its density?

Accepted Answer

$$0.789\ \mathrm{g/mL}$$

Question 19

Which of the following is a real-life example of a physical change?

Accepted Answer

Boiling water

Question 20

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

Accepted Answer

A compound is composed of elements chemically combined in fixed ratios, while a mixture is a physical combination of substances

CHEM 110 Lab Exam 1 Study Guide: Matter, Measurement, and Chemical Composition

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