Question 1

Which of the following best describes the difference between a scientific law and a scientific theory?

Accepted Answer

A law is a brief statement that summarizes a series of related observations; a theory provides the underlying reasons for those observations.

Question 2

A sample of a substance has a mass of $$2.36\ \mathrm{g}$$ and occupies a volume of $$7.98\ \mathrm{mL}. $$What is the density of the substance?

Accepted Answer

$$0.296\ \mathrm{g/mL}$$

Question 3

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

Accepted Answer

Iron rusting in moist air

Question 4

A student measures the mass of a lead block three times and records $$10.49\ \mathrm{g}$$, $$10.31\ \mathrm{g}$$, and $$10.13\ \mathrm{g}. $$The true mass is $$10.00\ \mathrm{g}. $$Which statement best describes the student's measurements?

Accepted Answer

The measurements are accurate but not precise.

Question 5

Which of the following is a homogeneous mixture?

Accepted Answer

Sweetened tea

Question 6

Which of the following statements about energy is correct?

Accepted Answer

Energy is always conserved in a physical or chemical change.

Question 7

A sample of gasoline is ignited and burns completely. Which property of gasoline is being demonstrated?

Accepted Answer

Chemical property

Question 8

Which of the following is an example of an intensive property?

Accepted Answer

Density

Question 9

A mixture of sand and water can be separated by which technique?

Accepted Answer

Decanting

Question 10

Convert $$12.00$$ inches to centimeters. ($$1\ \mathrm{in} = 2.54\ \mathrm{cm})$$

Accepted Answer

$$30.5\ \mathrm{cm}$$

Question 11

Which of the following is a correct statement about the SI base units?

Accepted Answer

The SI unit for mass is the kilogram ($$\mathrm{kg}).$$

Question 12

A student adds $$17.5\ \mathrm{mL}$$ and $$0.675\ \mathrm{mL}$$ using a calculator and gets $$18.175\ \mathrm{mL}. $$What is the answer reported to the correct number of significant figures?

Accepted Answer

$$18.2\ \mathrm{mL}$$

Question 13

Which of the following is a derived SI unit?

Accepted Answer

Liter ($$\mathrm{L})$$

Question 14

Which of the following is a correct conversion factor for converting $$\mathrm{in}^2 to$$ $$\mathrm{cm}^2$$?

Accepted Answer

$$1\ \mathrm{in}^2 = 6.45\ \mathrm{cm}^2$$

Question 15

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

Accepted Answer

A mixture of sand and salt

Question 16

Which of the following statements about physical and chemical properties is correct?

Accepted Answer

A physical property can be observed without changing the composition of a substance.

Question 17

A block of metal has a mass of $$825\ \mathrm{g}$$ and a volume of $$1.00\ \mathrm{L}. $$What is its density in $$\mathrm{g/L}$$?

Accepted Answer

$$825\ \mathrm{g/L}$$

Question 18

Which of the following is a correct statement about significant figures?

Accepted Answer

Trailing zeroes after a decimal point are always significant.

Question 19

Which of the following is a correct statement about the states of matter?

Accepted Answer

Liquids have a fixed volume but not a fixed shape.

Question 20

A sample of water is heated from $$25^\circ\mathrm{C} to$$ $$100^\circ\mathrm{C}. $$Which of the following best describes the change?

Accepted Answer

Physical change

Chapter 1: Matter, Measurement, and Problem Solving (General Chemistry Study Notes)

Guida di studio - Domande di pratica

Study guide - Flashcard