Chapter 1

List three differences and three similarities between a compound and an element.

What is in the space between the particles that make up a gas?

A pot of water on a stove is heated to a rapid boil. Identify the gas inside the bubbles that form in the boiling water.

A brief winter storm leaves a dusting of snow on the ground. During the sunny but very cold day after the storm, the snow disappears even though the air temperature never gets above freezing. If the snow didn't melt, where did it go?

Which of the following are homogeneous mixtures? (a) a gold wedding ring; (b) sweat; (c) bottled drinking water; (d) human blood; (e) compressed air in a scuba tank

Indicate whether each of the following properties is a physical or a chemical property of the element sodium: a. Its density is greater than that of kerosene and less than that of water. b. It has a lower melting point than that of most metals. c. It is an excellent conductor of heat and clectricity. d. It is soft and can be easily cut with a knife. e. Freshly cut sodium is shiny, but it rapidly tarnishes in contact with air. I. It reacts very vigorously with water to form hydrogen gas \(\left(\mathrm{H}_{2}\right)\) and sodium hydroxide \((\mathrm{NaOH})\).

Indicate whether each of the following is a physical or a chemical property of hydrogen gas \(\left(\mathrm{H}_{2}\right):\) a. At room temperature, its density is less than that of any other gas. b. It reacts vigorously with oxygen \(\left(\mathrm{O}_{2}\right)\) to form water. c. Liquefied \(\mathrm{H}_{2}\) boils at a very low temperature \(\left(-253^{\circ} \mathrm{C}\right)\) d. \(\mathrm{H}_{2}\) gas does not conduct electricity.

Which of the following is not a pure substance? (a) air; (b) nitrogen gas; (c) oxygen gas; (d) argon gas; (e) table salt (sodium chloride)

Which of the following is a pure substance? (a) sweat; (b) blood; (c) brass (an alloy of copper and zinc); (d) sucrose (table sugar); (e) milk

Which of the following is an element? (a) \(\mathrm{Cl}_{2} ;\) (b) \(\mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{HCl}\); (d) \(\mathrm{NaCl}\)

Which of the following is not an element? (a) \(\mathrm{I}_{2} ;\) (b) \(\mathrm{O}_{3}\) (c) \(\mathrm{ClF} ;\) (d) \(\mathrm{S}_{8}\)

Which of the following is a homogeneous mixture? (a) filtered water; (b) chicken noodle soup; (c) clouds; (d) trail mix snack; (e) fruit salad

Which of the following is a heterogeneous mixture? (a) air; (b) sugar dissolved in water; (c) muddy river water; (d) brass; (e) table salt (sodium chloride)

Which of the following can be separated by filtration? (a) sugar dissolved in coffee; (b) sand and water; (c) gasoline; (d) alcohol dissolved in water; (e) damp air

Would filtration be a suitable way to separate dissolved proteins from blood plasma? Explain why or why not.

Which of the following is an example of a chemical property of formaldehyde (CH \(_{2} \mathrm{O}\) )? a. It has a characteristic acrid smell. b. It is soluble in water. c. It burns in air. d. It is a gas at room temperature. e. It is colorless.

Which of the following is an example of a physical property of silver \((\mathrm{Ag}) ?\) a. It tarnishes over time. b. Tarnished silver can be cleaned to a shiny metallic finish. c. It reacts with chlorine to make a white solid. d. It sinks in water.

Can an extensive property be used to identify a substance? Explain why or why not.

Which of these propertics of water are intensive and which are extensive propertics? a. The density of water at room temperature and pressure. b. The temperature at which water freezes. c. The mass of water in your body. d. The mass of one molecule of water. e. The rate at which water is flowing over Niagara Falls.

What kinds of information are needed to formulate a hypothesis?

How does a hypothesis become a theory?

Is it possible to disprove a scientific hypothesis?

Why was the belief that matter consists of atoms considered a philosophy in ancient Greece, but a theory by the early \(1800 s ?\)

How do people use the word theory in normal conversation?

Can a theory be proven?

Describe in general terms how the SI and U.S. customary systems of units differ.

Suggest two reasons why SI units are not more widely used in the United States.

How many grams are there in 1.65 lbs?

How many pounds are there in \(765.4 \mathrm{g} ?\)

How many milliliters are there in 2.44 gal?

How many gallons are there in \(108 \mathrm{mL} ?\)

A swimming pool is \(1.12 \mathrm{m}\) decp at one end and 72 in decp at the other. Which is the deeper end?

There are ten steps from the sidewalk up to the front door of a student's apartment. Each tread is 5.0 inches deep and 6.0 inches above the previous one. What is the distance diagonally from the bottom of the steps to the top in centimeters?

A swimming pool is \(7.5 \mathrm{ft}\) deep, 42 ft wide, and \(65 \mathrm{ft}\) long, and it is filled to the brim with water. What is the volume of water in the pool in cubic inches?

Boston Marathon To qualify to run in the 2015 Boston Marathon, a distance of 26.2 miles, an 18 -year-old woman had to have completed another marathon in 3 hours and 34 minutes, or less. To qualify, what must this woman's average speed have been (a) in miles per hour and (b) in meters per second?

Olympic Mile An Olympic "mile" is actually \(1500 \mathrm{m}\). What percentage is an Olympic mile of a U.S. mile (5280 feet)?

If a wheelchair-marathon racer moving at 13.1 miles per hour expends energy at a rate of 665 Calories per hour, how much energy in Calories would be required to complete a marathon race ( 26.2 miles) at this pace?

A small hot-air balloon is filled with \(1.00 \times 10^{6} \mathrm{L}\) of air \((d=1.20 \mathrm{g} / \mathrm{L}) .\) As the air in the balloon is heated, it expands to \(1.09 \times 10^{6} \mathrm{L} .\) What is the density of the heated air in the balloon?

What is the volume of \(1.00 \mathrm{kg}\) of mercury?

A student wonders whether a piece of jewelry is made of pure silver. She determines that its mass is 3.17 g. Then she drops it into a 10 mL graduated cylinder partially filled with water and determines that its volume is \(0.3 \mathrm{mL}\). Could the jewelry be made of pure silver?

The Density of Blood The average density of human blood is \(1.06 \mathrm{g} / \mathrm{mL} .\) What is the mass of blood in an adult with a blood volume of 5.5 L? Express your answer in (a) grams and (b) ounces.

The Density of Earth Earth has a mass of \(5.98 \times 10^{24} \mathrm{kg}\) and a volume of \(1.08 \times 10^{12} \mathrm{km}^{3} .\) What is the average density of our planet in units of grams per cubic centimeter?

The mass of a diamond is usually expressed in carats, where 1 carat \(=0.200 \mathrm{g} .\) The density of diamond is \(3.51 \mathrm{g} / \mathrm{cm}^{3}\) What is the volume of a 5.0 -carat diamond?

If the concentration of mercury in the water of a polluted lake is 0.33 micrograms per liter, what is the total mass of mercury in the lake, in kilograms, if the lake has a surface area of \(10.0 \mathrm{km}^{2}\) and an average depth of \(15 \mathrm{m} ?\)

Which confidence interval is the largest for a given value of \(n: 50 \%, 90 \%,\) or \(95 \% ?\)

The concentration of ammonia in an aquarium tank is determined each day for a week. Which of these measures of the variability in the results of these analyses is greater: (a) mean \(\pm\) standard deviation or (b) \(95 \%\) confidence interval? Explain your selection.

If an outlier could not be identified at the \(95 \%\) confidence level, (a) could it be identified at the \(90 \%\) confidence level? (b) Could it be identified at the \(99 \%\) confidence level?

Which of these uncertain values has the smallest number of significant figures? (a) \(545 ;\) (b) \(6.4 \times 10^{-3} ;\) (c) 6.50 (d) \(1.346 \times 10^{2}\)

Which of these uncertain values has the largest number of significant figures? (a) \(545 ;\) (b) \(6.4 \times 10^{-3} ;\) (c) 6.50 (d) \(1.346 \times 10^{2}\)

Which of these uncertain values has the smallest number of significant figures? (a) \(1 / 545 ;\) (b) \(1 / 6.4 \times 10^{-3} ;\) (c) \(1 / 6.50\) (d) \(1 / 1.346 \times 10^{2}\)