AP Chemistry Homework

`AP Chemistry Homework

Chapter 1:

1. Identify each of the following substances as a gas, a liquid, or a solid under ordinary

conditions of temperature and pressure: (a) mercury, (b) sodium bicarbonate (baking

soda), (c) hydrogen, (d) carbon monoxide, (e) oxygen, (f) isopropyl alcohol,

(g) sodium chloride.

2. Indicate which of the following are physical processes and which are chemical

processes: (a) corrosion of aluminum metal, (b) cutting a diamond, (c) burning

gasoline, (d) boiling water.

3. A match is lit and held under a cold piece of metal. The following observations are

made: (a) The match burns. (b) The metal gets warmer. (c) Water condenses on the

metal. (d) Soot (carbon) is deposited on the metal. Which of these occurrences are

due to physical changes and which are due to chemical changes?

4. In the process of attempting to characterize a substance, a chemist makes the

following observations: The substance is a silvery-white, lustrous metal. It melts at

6490C and boils at 11050C. Its density at 200C is 1.738g/cm3. The substance burns in

air, producing an intense white light. It reacts with chlorine to give a brittle, white

solid. The substance can be pounded into thin sheets or drawn into wires. It is a good

conductor of electricity. Which of these characteristics are physical properties and

which are chemical properties?

5. Classify the following observations about a substance as either physical or chemical

properties: (a) color, (b) melting point, (c) reactivity with water, (d) boiling point,

(e) state of matter under ordinary conditions, (f) flammability, (g) density,

(h) electrical conductivity, (i) decomposition products upon heating.

6. Classify the following as a pure substance or a mixture; if a mixture, indicate whether

it is homogeneous or heterogeneous: (a) a chocolate-chip cookie, (b) water, (c) vodka,

(d) a pure gold coin, (e) air, (f) gasoline, (g) iodine crystals, (h) salad dressing.

7. Give the chemical symbol for each of the following elements: (a) carbon, (b) sodium,

( c) iron, (d) phosphorous, (e) potassium, (f) chlorine, (g) nitrogen, (h) silver.

8. Identify the chemical elements represented by the following symbols: (a) He, (b) Mg,

( c) Pb, (d) S, (e) F, (f) Zn, (g) Cu, (h) Ar.

9. In 1807, the English chemist Humphry Davy passed an electric current through

molton potassium hydroxide and isolated a bright, shiny, reactive substance. He

claimed the discovery of a new element, which he named potassium. In those days,

before the advent of modern instruments, what was the basis on which one could claim

that a substance was an element?

10. A solid white substance A is heated strongly in the absence of air. It decomposes to

form a new white substance B and a gas C. The gas has exactly the same properties

as the product obtained when carbon is burned in an excess of oxygen. What can we

say about whether solids A and B and the gas C are elements or compounds?

11. What basic SI units are appropriate for expressing the following quantities: (a) the

diameter of the earth, (b) the surface area of a tennis ball, (c) the volume of a gasoline

tank, (d) the mass of a brick, (e) the speed of light, (f) the temperature of the air,

(g) square miles, (h) quarts, (i) tons, (j) days, (k) yards, (l) degrees Fahrenheit.

12. What decimal power do the following abbreviations represent: (a) d, (b) c, (c) f,

(d) m, (e) M, (f) k, (g) n, (h) m, (i) p?

13. Use appropriate metric prefixes to write the following measurements without the use

of exponents: (a) 3.4 x 10-12m, (b) 4.8 x 10-6mL, (c) 7.23 x 103g, (d) 2.35 x 10-6m3,

(e) 5.8 x 10-9s, 3.45 x 10-3mol.

14. What type of quantity (for example, length, volume, density) do the following units

indicate? (a) mL, (b) cm2, (c) mm3, (d) mg/L, (e) ps, (f) nm, (g) K.

15. Indicate whether the following are measurements of length, area, volume, mass,

density, time, or temperature: (a) 5 ns, (b) 3.2 kg/L, (c) 0.88 pm, (d) 540 km2,

(e) 173 K, (f) 2 mm2, (g) 230C.

16. Perform the following conversions: (a) 454 mg to g, (b) 5.0 x 10 –8m to nm,

( c) 0.076mL to mL, (d) 1.55 kg/m3 to g/L, (e) 3.05 x 105g to kg, (f) 0.0025mm to pm,

(g) 3.45 x 10-8s to ns, (h) 4.5 x 108pm3 to m3.

17. (a) A sample of chloroform, a liquid once used as an anesthetic, has a mass of

37.25 g and a volume of 25.0 mL. What is its density? (b) The density of platinum

23.4 g/cm3. Calculate the mass of 50.0 cm3 of platinum. ( c) The density of

magnesium is 1.74 g/cm3. What is the volume of 175 g of this metal? (d) A cube of

plastic 1.2 x 10-5 km on a side has a mass of 1.1 g. What is the density in g/cm3?

Will this material float on water? (e) The density of liquid bromine is 3.12 g/mL.

What is the mass of 0.500 L of bromine? (f) The density of a piece of ebony wood is

1.20 g/cm3. What is the volume of 8.74 kg of this wood?

18. Make the following temperature conversions: (a) 680F to 0C, (b) –36.70C to 0F,

( c) –150C to K, (d) 415 K to 0F, (e) 15000F to K, (f) 920F to 0C, (g) 8040C to K,

(h) 234.28 K to 0F.

19. Indicate which of the following are exact numbers: (a) the number of inches in a

mile, (b) the diameter of a dime, (c) the mass of a 12 oz bag of potato chips, (d) the

number of ounces in a pound, (e) the number of micrometers in a kilometer, (f) the

number of inches in a kilometer, (g) the mass of a Nerf ball, (h) the number of seconds

in a year, (i) the surface area of a penny, (j) the temperature of the surface of the sun,

(k) the number of mL in a cubic foot of water, (l) the number of pages in this book..

20. What is the number of significant figures in each of the following measured

quantities? (a) 122g; (b) 0.002796 s; (c) 8.07 mm; (d) 0.01050 L; (e) 5.7750 X 10-4

cm3, (f) 3.141 cm; (g) 0.000050 m2; (h) 3,480,200 s; (i) –1.200oC; (j) 1.0800 X

10-2 L.

21. Round each of the following numbers to four significant figures: (a) 12,345,670; (b)

2.35500; (c) 456,500; (d) 3.218 X 103; (e) 0.000657030; (f) 100,500.1.

22. Round each of the following numbers to three significant figures: (a) 10.000; (b)

0.05000; (c) 23,00; (d) 1.565 X 101; (e) 9,834.05; (f) –1235.

23. Carry out the following operations and express the answers with the appropriate

number of significant figures: (a) 1.23056 + 67.809; (b) 23.67 – 500; (c) 890.05 X

12.3; (d) 88, 132/22.500; (e) 324 – (6104.5/22.3); (f) [(285.3 X 106) – (12.000 X 103)];

(g) (0.0045 X 30,000.0) + (283 X 12); (h) 869 X [1255- (3.45 X 103)].

24. Perform the following conversions: (a) 3.60 mi to m; (b) 2.00 days to s; (c) $1.95/gal

to dollars per liter; (d) 5.0 pm/us to m/s; (e) 85.00 mi/hr to m/s; (f) 33.35 ft3 to cm3.

(g) 7.5 ft to cm; (h) 4.45 qt to mL; (i) 35.7 in/hr to mm/s; (j) 2.00 yd3 to m3; (k) $3.99

per pound to pennies per gram.

25. (a) If the gasoline tank of a compact car has a capacity of 12 U.S. gal, what is its

capacity in liters? (b) If a bee flies at an average speed of 3.4 m/s, what is its average

speed in mi/hr? (c) What is the engine piston displacement in liters of an engine whose

displacement is listed as 320 in3? (d) How many liters of wine can be held in a wine

barrel whose capacity is 31 gal? (e) The recommended adult dose of Elixophyllin a

drug used to treat asthma, is 6 mg/kg of body mass. Calculate the dose in milligrams

for a 170-lb person. (f) If an automobile is able to travel 244 mi on 11.2 gal of for a

170-lb person. (g) If an automobile is able to travel 244 mi on 11.2 gal of gasoline,

what is the gas mileage in km/L?

26. The density of air at ordinary atmospheric pressure and 25oC is 1.19 g/L. What is

the mass, in kilograms, of the air in a room that measures 8.2 X 13.5 X 2.75 m?

27. The maximum allowable concentration of carbon monoxide in urban air is 10 mg/m3

over an 8-hr period. At this level, what mass of carbon monoxide is present in a room

measuring 8 X 12 X 20 ft?

28. Mercury is traded by the “flask,” a unit that has a mass of 34.5 kg. What is the

volume of a flask of mercury if the density of mercury is 13.6 g/mL?

29. The Morgan silver dollar has a mass of 26.73 g. By law, it was required to contain

90 percent silver, with the remainder being copper. (a) When the coin was minted in

the late 1800s, silver was worth $1.18 per troy ounce (31.1 g). At this price, what is

the value of the silver in the silver dollar? (b) Today, silver sells for $3.70 per troy

ounce. How many silver dollars are required to obtain $25.00 of pure silver.

30. In March 1989, the Exxon Valdez ran aground and spilled 240,000 gallons of crude

petroleum off the coast of Alaska. One barrel of petroleum is equal to 42 gal. How

many milliliters of petroleum were spilled? 31. A pound of coffee beans yields 50

cups of coffee (4 cups = 1 qt). How many milliliters of coffee can be obtained from 1

g of coffee beans?

32. Which of the following are intensive properties: (a) mass; (b) density;

(c) temperature; (d) area; (e) color; (f) volume. 33. (a) What is the difference between a hypothesis and a theory? (b) What is the

difference between a theory and a scientific law? Which addresses how matter

behaves, and which addresses why it behaves that way?

34. A sample of ascorbic acid (vitamin C) is synthesized in the laboratory. It contains

1.50g of carbon and 2.00g of oxygen. Another sample of ascorbic acid isolated from

citrus fruits contains 6.35g of carbon. How many grams of oxygen does it contain?

Which law does this illustrate?

35. Give the derived SI units for each of the following quantities in terms of base SI

units: (a) acceleration = distance/time2; (b) force = mass X acceleration; (c) work =

force X distance; (d) pressure = force/area; (e) power = work/time.

36. Magnesium is used in automobile wheels because it is “lighter” than steel. What is

a more scientifically correct statement of this

37. Is the use of significant figures in each of the following statements appropriate?

Why or why not? (a) The 1976 circulation of Reader’s Digest was 17,887,299.

(b) There are more than 1.4 million people in the United States who have the surname

Brown. (c) The average annual rainfall in San Diego, California, is 20.54 in. (d) The

population of East Lansing, Michigan, was 51,237 in 1979.

38. The annual production of sodium hydroxide in the United States in 1991 was

24.69 billion pounds. (a) How many grams of sodium hydroxide were produced in that

year? (b) The density of sodium hydroxide is 2.130g/cm3. How many cubic kilometers

were produced?

39. You are given a bottle that contains 2.36 mL of a yellow liquid. The total mass of

the bottle and the liquid is 5.26g. The empty bottle weighs 3.01g. What is the density

of the liquid? 40. An 8.47-g sample of a solid is placed in a 25.00-mL flask. The

remaining volume in the flask is filled with benzene in which the solid is insoluble.

The solid and the benzene together weigh 24.54g. The density of the benzene is

0.879g/mL. What is the density of the solid?

41. The U.S. quarter has a mass of 5.67g and is approximately 1.55mm thick. (a) How

many quarters would have to be stacked to reach 575ft, the height of the Washington

Monument? (b) How much would this stack weigh? (c) How much money would this

stack contain? (d) At this writing, the national debt is $4.2 trillion. How many stacks

like the one described would be necessary to pay off this debt?

42. A piece of aluminum foil measuring 12.0 in. by 15.5 in. has a mass of 5.175g.

Aluminum has a density of 2.70g/cm3. What is the thickness of the foil in millimeters?

43. A cylindrical glass tube 15.0cm in length is filled with ethanol. The mass of

ethanol needed to fill the tube is found to be 9.64g. Calculate the inner diameter of the

tube in centimeters. The density of ethanol is 0.789g/mL.

44. Chromatography is a simple but reliable method for separating a mixture into its

constituent substances. Suppose you are using chromatography to separate a mixture

of two substances. How would you know whether the separation is successful? Can

you propose a means of quantifying how good or how poor the separation is?

45. Suppose you are given a sample of a homogeneous liquid. What would you do to

determine whether it is a solution or a pure substance?

46. The distance from Earth to the moon is approximately 240,000mi. (a) What is the

distance in millimeters. (b) The Concorde SST has an airspeed of about 2400km/hr. If

the Concorde could fly to the moon, how many mega-seconds would it take?