Chapter 1 review

Question 1

Which of the following steps is not a part of the scientific method?

Answer 1

• Formulate a theory based on a single observation

Question 2

Which statement most accurately describes the discipline of chemistry?

Answer 2

• Chemistry helps us understand the behavior of materials at an atomic or molecular level.

Question 3

What distinguishes a mixture from a pure substance?

Answer 3

• A mixture is a combination of two or more substances that are physically separable, and a pure substance is not physically separable

Question 4

The melting point of the metal gallium is 30°C. Normal body temperature is about 37°C. When a person holds a piece of gallium, it tends to melt. This is an example of what type of change?

Answer 4

• a physical change

Question 5

A student makes measurements of a line. The student records the lengths as 20.5, 20.4, and 20.2. Which statement best describes this data?

Answer 5

• It is impossible to say.

Question 6

One kilogram is equal to about 2.20 pounds. Both kilograms and pounds are units of mass. What is the equivalent weight in pounds of a 37.5 kilogram object?

Answer 6

• 82.5 lb

Question 7

Which of the following statements best describes the implied uncertainty of a measurement?

Answer 7

• Because any measurement device is limited by how small its units are, there is always an uncertainty in the last digit of a measurement.

Question 8

There are always two conversion factors to choose from for every conversion that you want to do (e.g. 12 in./1 ft or 1 ft/12 in.). Which statement best describes why you should multiply by one conversion factor and not the other?

Answer 8

• When choosing a conversion factor, you have to know what units your data is presented in (i.e. your original piece of data) and what units you want to convert to. You want to choose the conversion factor that will cancel the original units, leaving the new units.

Question 9

Which of the following statements violates the stated rules (or conventions) for significant figures?

Answer 9

• 0.29000100 has six significant figures.

Question 10

Which of the following multiplication or division problems is not correct with respect to significant figures?

Answer 10

• 2.5 ⋅ 18.401 = 46.0

Question 11

After being cited for speeding, you take your car to the shop to have the speedometer tested. They discover that all speeds are reported 10% lower than the true speed. What is this an example of?

Answer 11

• systematic error

Question 12

A baseball is thrown at 42.5 m / s (that’s meters per second). What is the speed of the baseball in miles / hour? (1 mi = 5280 ft, 1 in = 2.54 cm)

Answer 12

• 95.1 mi / hr

Question 13

A physical property, such as mass or volume, that depends on the amount of matter, is called

Answer 13

• an extensive property

Question 14

Which of the following is an extensive physical property?

Answer 14

• mass

Question 15

Chemists categorize matter into three different phases or states. Which of the following is not a general phase or state of matter?

Answer 15

• solution

Question 16

Which of the following is not a mixture?

Answer 16

• oxygen gas

Question 17

Which of the following is not a base SI unit?

Answer 17

• inch

Question 18

Suppose you are measuring heights of students. You have been using a measuring tape whose smallest unit is centimeters. Which of the following options would give you the greatest improvement in the precision of your readings?

Answer 18

• Use a measurement tape that has units of millimeters as its smallest unit.

Question 19

In carrying out the experiment of burning paper and making observations, which of the following was not a simple observation that was made about the properties involved in the experiment?

Answer 19

• Ashes from burnt paper weigh more than the unburnt paper.

Question 20

According to Dalton’s atomic theory of matter, what happens during a chemical reaction?

Answer 20

• Atoms rearrange to form new compounds.