Question 1

A large pizza has a diameter of 15 inches. Express this diameter in centimeters. (1 in = 2.54 cm)

Accepted Answer

A)  38 cm 
B)  24 cm 
C)  18 cm 
D)  9.3 cm 
E)  5.9 cm

Question 2

Melting ice is a ________ change.

Accepted Answer

The answer of Melting ice is a ________ change....

Question 3

When applying the scientific method, a model or theory should be based on experimental data.

Accepted Answer

A) True 
 B)False

Question 4

Which of the following represents the greatest mass?

Accepted Answer

A)  2.0 x 103 mg 
B)  10.0 dg 
C)  0.0010 kg 
D)  1.0 x 106 µg 
E)  3.0 x 1012 pg

Question 5

Dry ice (carbon dioxide) changes from a solid to a gas at -78.5°C. What is this temperature in °F?

Accepted Answer

A)  -173°F 
B)  -12.6°F 
C)  -109°F 
D)  -75.6°F 
E)  None of them is within 2°F of the right answer.

Question 6

Which one of these represents a physical change?

Accepted Answer

A)  Water, when heated, forms steam. 
B)  Bleach turns hair yellow. 
C)  Sugar, when heated, becomes brown. 
D)  Milk turns sour. 
E)  Apples, when exposed to air, turn brown.

Question 7

Explain the difference between quantitative measurements and qualitative measurements.

Accepted Answer

The answer of Explain the difference between quantitative measurements and...

Question 8

The mass of a sample is 550 milligrams. Which of the following expresses that mass in kilograms?

Accepted Answer

A)  5.5 × 108 kg 
B)  5.5 × 105 kg 
C)  5.5 × 10-4 kg 
D)  5.5 × 10-6 kg 
E)  5.5 × 10-1 kg

Question 9

The juice from an orange is a mixture.

Accepted Answer

A) True 
 B)False

Question 10

If two numbers are added together, one which has 2 digits after the decimal point and the other which has 1 digit after the decimal point, explain how to round the answer.

Accepted Answer

The answer of If two numbers are added together, one...

Question 11

How many inches are in 382.5 cm? (1 in = 2.54 cm)?

Accepted Answer

A)  150.6 in 
B)  6.641 × 10-3 in 
C)  151 in 
D)  971.6 in 
E)  972 in

Question 12

Which of the following does not have a uniform composition throughout?

Accepted Answer

A)  Element 
B)  Compound 
C)  Homogeneous mixture 
D)  Heterogeneous mixture 
E)  Solvent

Question 13

The average distance between the Earth and the Moon is 240,000 miles. Express this distance in meters. (1 mi = 1609 m)

Accepted Answer

A)  6.1 × 105 m 
B)  5.3 × 105 m 
C)  3.9 × 108 m 
D)  1.5 × 105 m 
E)  9.4 × 104 m

Question 14

The city of Los Angeles is now approximately 2400 miles south of Anchorage, Alaska. It is moving slowly northward as the San Andreas fault slides along. If Los Angeles is to arrive near Anchorage in 76 million years, at what average rate will it have to move in mm per month? (1 mi = 1609 m)

Accepted Answer

A)  2.0 × 10-10 mm/mo. 
B)  6.6 × 10-6 mm/mo. 
C)  4.2 mm/mo. 
D)  9.5 mm/mo. 
E)  51 mm/mo.

Question 15

Explain the difference between accuracy and precision.

Accepted Answer

The answer of Explain the difference between accuracy and precision....

Question 16

If you have a graduated cylinder containing 15.5 mL of water and this volume increases to 95.2 mL after a piece of metal with a mass of 7.95 g is dropped into the graduated cylinder, then what is the density of the metal?

Accepted Answer

A)  0.0835 g/mL 
B)  0.513 g/mL 
C)  0.0718 g/mL 
D)  10.0 g/mL 
E)  9.97 × 10-2 g/mL

Question 17

Select the answer that expresses the result of this calculation with the correct number of significant figures.

Accepted Answer

A)  13.3568 
B)  13.357 
C)  13.36 
D)  13.4 
E)  13

Question 18

Which of the following properly expresses 0.01234 in scientific notation?

Accepted Answer

A)  1.234 × 10-3 
B)  12.3 × 104 
C)  1 × 10-1  
D)  1.234 × 102 
E)  1.234 × 10-2

Question 19

What is something that has a definite composition?

Accepted Answer

The answer of What is something that has a definite...

Question 20

A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the temperature of the measurement.)

Accepted Answer

A)  1.992 g/cm3 
B)  1.840 g/cm3 
C)  1.729 g/cm3  
D)  1.598 g/cm3 
E)  0.543 g/cm3

Exam 1: Chemistry: the Central Science