Chapter 2

Question 1

Scientists use a specific format to express large or small numbers. What is the notation called?

Two word answer

Answer 1

scientific notation

Question 2

True or False

Consider this statement:
‘‘Measurements are used by chemists to better understand matter.’’

Answer 2

True

Question 3

Chemistry is an experimental science; that is, chemical discoveries are made as a result of ____\

Single word answer

Answer 3

• experiments
• experimentation

Question 4

True or False

Consider this statement:
‘‘Qualitative observations use numbers.’’

Answer 4

False

Question 5

True or False

Consider this statement:
‘'’An oral dose of 5 cc. is a qualitative measurement’’

Answer 5

False

Question 6

True or False

Consider this statement:
‘‘Quantitative and qualitative observations are both used to describe the physical properties of matter’’

Answer 6

True

Question 7

To completely describe a substance, one or more ____\ measurements must be taken.

Single word answer

Answer 7

quantative

Question 8

What types of numbers are considered exact or without error in the presented value?
* counted numbers (regardless of their magnitude)
* counted numbers (but only below a reasonable limit and under controlled conditions)
* simple fractions
* defined numbers

Answer 8

• counted numbers (but only below a reasonable limit and under controlled conditions)
• simple fractions
• defined numbers

Question 9

True or False

Consider the statement:
‘‘If you have 1/2 dollar you have exactly 50 cents.’’

Answer 9

True

Question 10

True or False

Consider the statement:
‘‘All counted numbers are considered exact.’’

Answer 10

False

Question 11

True or False

Consider the statement:
‘‘There are 100 cents in one dollar.’’
In this statement, the number 100 is an exact number.

Answer 11

True

Question 12

True or False

Consider the statement:
‘‘There are 4,555 people in the stadium attending the soccer match.’’
In this statement, the number 4,555 is an exact number.

Answer 12

False

Question 13

Consider the statement:
‘‘A machinist determines the length of an aluminum rod to be 5 inches.’’
In this statement, is the number 5 an exact number or an inexact number?

Answer 13

inexact number

Question 14

How close to each other multiple measured results obtained in the same fashion are to each other is a measure of?

Single word answer

Answer 14

Precision

Question 15

How close a result is to its true value is a measure of?

Single word answer

Answer 15

• accuracy
• exactness

Question 16

True or False

When comparing two instruments, the more precise instrument will always be the more accurate one

Answer 16

False

Question 17

Which depends on the physical measuring device used to make the measurement?
* Accuracy
* Precision
* Both accuracy and precision

Answer 17

• Both accuracy and precision

Question 18

Which depends on the skill of the person performing the measurement?
* Accuracy
* Precision
* Both accuracy and precision

Answer 18

• Both accuracy and precision

Question 19

What type(s) of error(s) is/are associated with measurements?
* random errors
* systematic errors
* random and systematic errors

Answer 19

• random and systematic errors

Question 20

How does a chemist control or minimize random errors?

Answer 20

• control the environment of the experiment
• through calculations to remove error from the data
• control the enviroment and calculations to remove error

Question 21

Consider the following task: Determine the gas mileage of two cars. To complete the task, you need to decide which parameters affect gas mileage. Let’s assume that you came up with these factors: car type and size of engine, car age, driving habits of all drivers using the car, weather conditions, traffic conditions, tire inflation.

Which of the factors would cause respectively random and systematic errors in your determination of gas mileage?

Car Type:
Engine Size:
Age of car:
Driving habits of all drivers using the car:
Weather conditions:
Traffic conditions:
Tire inflation:

Answer 21

Car Type: Systematic error
Engine Size: Systematic error
Age of car: Systematic error
Driving habits of all drivers using the car: Random error
Weather conditions: Random error
Traffic conditions: Random error
Tire inflation: Systematic error

Question 22

How many digits in a measurement are estimated?

Answer 22

one

Question 23

True or False

Consider the statement:
‘‘The uncertainty (error estimate) of a measured value is always presented in the last recorded significant digit.’’

Answer 23

True

Question 24

What is the error in the measured quantity 75 degrees?
* ±5 degrees
* ±1degree
* ±0.1 degree
* ±0.05 degree
* ±0.01 degree

Answer 24

• 1degree

Question 25

What is the error in the measured quantity 25.6 mL? * ±1 ml * ±0.1 ml * ±0.6 ml * ±5.6 ml * ±6 ml

Answer 25

* 0.1 ml

Question 26

What is the error in the measured quantity 105.43 meters? * ± 0.43 meters * ± 0.4 meters * ± 0.03 meters * ± 0.01 meters * ± 0.001 meters

Answer 26

* 0.01 meters

Question 27

For a temperature measured to 75.43 degrees, what would be the smallest calibration marks on the thermometer used to make this measurement? * whole degrees * tenths of a degree * hundredths of a degree * thousandths of a degree * none of the above is correct

Answer 27

* tenths of a degree

Question 28

What are the two types of information conveyed when a measured value is recorded? * size or magnitude * the behavior of matter * uncertainty of error * the physical state

Answer 28

* size or magnitude * uncertainty of error

Question 29

A digit that is either reliably known or estimated is a _\_\_\_\

Answer 29

* significant figure * sig fig * sig. fig.

Question 30

What types of numbers are considered exact or without error in the presented value? * (small) counted numbers * simple fractions * measured numbers * defined numbers

Answer 30

* (small) counted numbers * simple fractions * defined numbers

Question 31

What is the error or magnitude of uncertainty (±) in the distance to the moon presented above (234 000)?

Answer 31

1000

Question 32

How many significant figures are in the measured value 0.30574?

Answer 32

5

Question 33

How many significant figures are in the measured value 550,000,000?

Answer 33

2

Question 34

How many significant figures are in the measured value 37.50?

Answer 34

4

Question 35

How many significant figures are in the measured value 0.002090?

Answer 35

4

Question 36

How many significant figures are in the measured value 30,000.500?

Answer 36

8

Question 37

How many significant figures are in one dozen?

Answer 37

* infinite * infinity * limited * no limit * undefined * not defined * infinite number

Question 38

How many significant figures are in ¼ dozen?

Answer 38

* infinite * infinity * limited * no limit * undefined * not defined * infinite number

Question 39

What is the magnitude of uncertainty in the measured value 550,000,000? * ±1 * ±100 * ±1000 * ±100,000 * ±1,000,000 * ±10,000,000 * ±100,000,000

Answer 39

* ±10,000,000

Question 40

What is the magnitude of uncertainty in the measured value 37.50? * ±0.001 * ±0.01 * ±0.1 * ±0.50 * ±0.5 * ±7.5

Answer 40

* ±0.01

Question 41

What is the magnitude of uncertainty in the measured value 0.02090? * ±0.001 * ±0.0001 * ±0.00001 * ±0.000001 * ±0.0000001

Answer 41

* ±0.00001

Question 42

# True or False Consider this statement: "Mathematical operations should neither increase nor decrease the uncertainty of experimental measurements."

Answer 42

True

Question 43

# True or False or Depends Consider this statement: "When computing a result with measured numbers on a calculator, all the digits displayed by the calculator are significant."

Answer 43

Depends

Question 44

188,501 rounded to three significant figures becomes

Answer 44

189,000

Question 45

# True or False Consider the following statement: "The number 3.746 rounded off to two significant figures can first be rounded to 3.75, and then to 3.8."

Answer 45

False

Question 46

0.0038965 rounded to four significant figures becomes

Answer 46

0.003896

Question 47

145,789 rounded off to three significant figures becomes

Answer 47

146,000

Question 48

172.540 rounded off to two significant figures becomes

Answer 48

170

Question 49

95,000 rounded off to one significant figure becomes

Answer 49

100,000

Question 50

# True or False To determine how many significant figures should be reported in a sum or difference, the total of significant figures in each term is counted. The result will have the same number of significant figures as term with the fewest significant figures.

Answer 50

False

Question 51

# True or False To determine how many significant figures should be recorded in a product or quotient, the answer must have the same uncertainty as the term with the largest uncertainty.

Answer 51

False

Question 52

In calculations involving both exact and inexact numbers, which numbers will be used to determine the significant figures in the answer? * exact numbers * inexact numbers * both, exact and inexact numbers

Answer 52

* inexact numbers

Question 53

If one candy bar weighs 2.13 ounces, what will be the total weight of nine such candy bars? | Use significant figure rules to properly round

Answer 53

19.17

Question 54

In order to simplify the writing of either very large or very small numbers, scientists use _\_\_\_\

Answer 54

scientific notation

Question 55

In terms of magnitude, is 1.25 x 10⁷ a big or a small number?

Answer 55

Big

Question 56

Is 23.45 x 10³ expressed in proper scientific notation?

Answer 56

No

Question 57

Consider the mathematical expression 4⁷. What is the base number?

Answer 57

4

Question 58

Consider the mathematical expression 4⁷. What is the exponent?

Answer 58

7

Question 59

What do you have to do before adding or subtracting scientific notation numbers? * Match the power of ten for all numbers. * Make sure all numbers are expressed in proper scientific notation. * Make sure all numbers have been converted from decimal to scientific notation. * No need to worry-the calculator will figure this out. | Multiple answers

Answer 59

* Match the power of ten for all numbers. * Make sure all numbers have been converted from decimal to scientific notation.

Question 60

What is the final step of an addition or subtraction involving scientific notation numbers? * Write down the number from the calculator display. * Check if the coefficient has the decimal in the correct location - make adjustments if necessary.

Answer 60

* Check if the coefficient has the decimal in the correct location - make adjustments if necessary.