mastering chemistry homework answers chapter 1

Classify each of the following substances as an element, a compound, or a mixture.
Drag the appropriate items to their respective bins.

Element: silver, Ag and fluorine, F Compound: carbon monoxide, CO and calcium chloride, Ca Cl2 Mixture: soft drink

Classify the following mixtures as homogeneous or heterogeneous.
Drag the appropriate items to their respective bins.

Homogeneous mixture: stainless steel, vodka, and gasoline Heterogeneous mixture: potato salad and gravel

A sample of wine consists of water, sugar, some amount of ethyl alcohol, and grape juice. These ingredients blend together uniformly to give clear and tasty wine.
Which term or terms could be used to describe this sample of wine?
Check all that apply.

-mixture -homogeneous mixture -solution

A copper foil is made from copper, absolutely free of impurities.
Which term or terms could be used to describe this sample of copper?
Check all that apply.

-pure chemical substances -element

A sample of beach sand contains sand particles of different colors, small pebbles, and also shells. Each component contains different metals and minerals. The pebbles and shells can easily be separated from the sand.
Which term or terms could be used to describe this sample of sand?
Check all that apply.

-mixture -heterogeneous mixture

A balloon is filled with pure carbon dioxide.
Which term or terms could be used to describe the contents of this balloon?
Check all that apply.

-pure chemical substance -compound

Classify the following as intensive or extensive properties of silver.
Drag the appropriate items to their respective bins.

Intensive: -begins to melt at 961.78 degrees Celsius -has a density of 10.49 g/mL -matte gray in color Extensive: -has a mas of 77.83 g -has a volume of 7.42 mL

You are given a sample resembling silver. Which of the following properties could be used to help determine whether the sample is really silver?
Check all that apply.

-the density of the sample -the melting point of the sample

Which of following changes that affect the composition of our atmosphere involve physical changes and which involve chemical reactions?
Drag the appropriate items to their respective bins.

Physical Change: -water vapor forms from frost as the air temperature rises. -clouds form when water vapor in the air condenses. Chemical Reaction: -microbes decompose complex organic matter to release carbon dioxide and methane. -carbon monoxide is produced by the combustion of gasoline. -most of the ozone is created as a byproduct of human-created photochemical smog.

In a laboratory experiment, a fermenting aqueous solution of glucose and yeast produces carbon dioxide gas and ethanol. The solution was heated by burning natural gas in a Bunsen burner to distill the ethanol that formed in the flask. During the distillation, the ethanol evaporated and then condensed in the receiving flask. The flame of the burner was kept too close to the bottom of the flask and some of the glucose decomposed into a black carbon deposit on the inside of the flask. During this experiment the following changes occurred.
Which of these changes involved a physical change and not a chemical change?
Check all that apply.

-condensation of ethanol -evaporation of ethanol

Which of the following properties of zinc are chemical properties?
Check all that apply.

-it burns under a flame giving off zinc oxide fumes. -it reacts with chlorine to form zinc chloride.

Which of the following properties of a ice cube are physical properties?
Check all that apply.

-it has a mass of 27.3 g. -it is hard. -it is cold to touch.

Convert the number 0.000127 to scientific notation, then enter the answer using the MasteringChemistry format.
Express your answer numerically.

1.27 x 10^-4

Use your calculator to determine the answer to the following calculation:
(1.0×10^-15)/(4.2×10^−7)
Express the answer in MasteringChemistry format using two significant figures.
Express your answer numerically using two significant figures.

-2.4 x 10^-9

4.3×10^−6 is between which two numbers?

1 x 10^-5 and 1 x 10^-6

Which of the following are equal to 5×10^10?
Check all that apply.

-50 x 10^9 -500 x 10^8 -0.5 x 10^11

How many milliliters of liquid does the smaller graduated cylinder contain?
Express your answer in milliliters using the proper number of significant figures.

3.54 mL

How many milliliters of liquid does the larger graduated cylinder contain?
Express your answer in milliliters using the proper number of significant figures.

1.5 L

If you could use only one of these graduated cylinders, which graduated cylinder would more precisely measure a given volume of liquid?

the smaller graduated cylinder

A particular brand of gasoline has a density of 0.737 g/mL at 25 ∘C. How many grams of this gasoline would fill a 12.7 gal tank (1US gal=3.78L)?
Express your answer to three significant figures and include the appropriate units.

3.54 x 10^4 g

A block of metal has a width of 3.2 cm, a length of 17.1 cm, and height of 4.5 cm . Its mass is 1.3 kg . Calculate the density of the metal.
Express your answer to two significant figures and include the appropriate units.

5.3 g/cm^3

The average normal human body temperature is 98.6 ∘F.
What is normal body temperature in degrees Celsius?
Express your answer numerically in degrees Celsius.

37.0 degrees Celsius

The average normal human body temperature is 98.6 ∘F.
What is normal body temperature in kelvins?
Express your answer in kelvins using four significant figures.

310.2 K

Rank the size of a change in temperature of one degree Fahrenheit, one degree Celsius, and one kelvin. In other words, if a thermometer were to show that the temperature outside increased by these amounts, which change would feel the largest? If any of the options are the same magnitude, stack them above one another.
Rank the sizes of one degree in each scale from largest to smallest. To rank items as equivalent, overlap them.

Largest to Smallest: -one kelvin and one Celsius degree (overlap) -one Fahrenheit degree

Compute 3.5×4.48697. Round the answer appropriately.
Express your answer numerically using the proper number of significant figures.

16

Compute 1240.64/12.5. Round the answer appropriately.
Express your answer numerically using the proper number of significant figures.

99.3

Compute 9.3456+2140.56. Round the answer appropriately.
Express your answer numerically using the proper number of significant figures.

2149.91

Compute 4659¯0−214¯00. Round the answer appropriately.
Express your answer numerically using the proper number of significant figures.

25200

Determine the number of significant figures in the measurement 6.07 m?
Express your answer numerically as an integer.

3

Determine the number of significant figures in the measurement 0.0030 s?
Express your answer numerically as an integer.

2

Round the value 44.981 g to three significant figures.
Express your answer numerically using three significant figures.

45.0 g

A bakery measured the mass of a whole cake as 0.870 kg. A customer bought one slice of the cake and measured the mass of the slice as 0.1151 kg. What is the mass of the remaining cake, without the one slice?
Express your answer in kilograms using the appropriate number of significant figures.

0.755 kg

An unknown object is placed on a balance, which then reads 6.118 g. Its volume is measured to be 3.04 cm3. Find the density of this object by dividing mass by volume.
Express your answer in grams per cubic centimeter to the appropriate number of significant figures.

2.01 g/cm^3

Rank the data sets in decreasing order of precision.
Rank from most to least precise. To rank items as equivalent, overlap them.

Most precise to least precise: -set 1 -set 2 -set 3

The accepted density of the sugar solution is 1.394 g/mL . Based on the average value of each data set, rank the data sets in decreasing order of accuracy.
Rank from most to least accurate. To rank items as equivalent, overlap them.

Most accurate to least accurate: -set 1 -set 3 -set 2

The conversion factor relating miles to meters is 1mile=1610m.
The speed of light is 3.00×10^8 m/s. How fast is this in miles per hour (miles/h)?

6.71 x 10^8 miles/h

The conversion factor relating feet to meters is 1ft=0.305m. Keep in mind that when using conversion factors, you want to make sure that like units cancel leaving you with the units you need.
You have been told that a certain house is 164 m2 in area. How much is this in square feet?

1760 ft^2

In the course of a conversation, you observe that three of your friends like horror movies. Horror movies happen to be your favorite type of movie as well. You also know that all of these friends were born in the same week that you were, even in the same year.
An astrology-loving friend hypothesizes that people born in that week like horror movies more than other genres of movies. You decide to use the scientific method to test this hypothesis.
What should you do next?

perform experiments to test your hypothesis.

Which of the following experiments would best test your hypothesis?

find other people born in the same week and ask them what their favorite type of movie is.

What should you do next?

refine your hypothesis

You wash dishes for a chemistry laboratory to make extra money for laundry. You earn 12 dollars/hour, and each shift lasts 75 minutes. Your laundry requires 12 quarters/load.
How many shifts must you work if you wish to wash 10 loads of laundry?
Express your answer numerically as an integer.

2 shifts

How many loads of laundry can you wash if you work 3 shifts?
Express your answer numerically as an integer.

15 loads

How many loads of laundry will each shift pay for if the cost per load rises to 16 quarters?
Express your answer numerically as an integer.

3 loads