Chapter 1

What steps are involved in the scientific method?

What is the difference between (a) a law and a theory, (b) an observation and a conclusion, (c) an observation and data?

Define matter. Which are examples of matter? (a) air, (b) an idea, (c) a bowl of soup, (d) a squirrel, (e) sodium chloride, \((\mathbf{f})\) the sound of an explosion

Define (a) element, (b) compound, (c) mixture, (d) homogeneous, (e) heterogeneous, (f) phase, (g) solution.

Which kind of change, chemical or physical, is needed to change a compound into its elements?

What is the chemical symbol for each of the following elements? (a) fluorine, (b) selenium, (c) nickel, (d) argon, (e) lithium, (f) phosphorus, (g) iodine, (h) gallium, (i) mercury, (j) manganese

What is the name of each of the following elements? (a) \(\mathrm{Na}\) (b) \(\mathrm{Zn}\) (c) \(\mathrm{Si}\) (d) \(\mathrm{Sn}\) (e) \(\mathrm{Mg}\), (f) W, (g) Co, (h) \(\mathrm{Al},(\mathrm{i}) \mathrm{O},(\mathrm{j}) \mathrm{N}\)

What is a physical change? What is a chemical change? What is the chief distinction between physical and chemical changes?

What is a physical change? What is a chemical change? What is the chief distinction between physical and chemical changes?

In places like Saudi Arabia, freshwater is scarce and is recovered from seawater. When seawater is boiled, the water evaporates and the steam can be condensed to give pure water that people can drink. If all the water is evaporated, solid salt is left behind. Are the changes described here chemical or physical?

How does a chemical property differ from a physical property?

Distinguish between an extensive and an intensive property.

Determine whether each of the following is an intensive or extensive property, and justify your reasoning: (a) mass (e) physical state (b) boiling point (f) density (c) color (g) volume (d) surface area

Why must measurements always be written with a unit?

What is the only SI base unit that includes a prefix?

Which SI units are mainly used in chemistry?

Which SI units are mainly used in chemistry?

What is the meaning of each of the following prefixes? What abbreviation is used for each prefix? (a) centi (e) nano (b) milli (f) pico (c) kilo (g) mega (d) micro

In each pair, which is larger: (a) A Fahrenheit degree or a Celsius degree? (b) A Celsius degree or a kelvin? (c) A Fahrenheit degree or a kelvin?

Define the term significant figures.

What is the difference between accuracy and precision?

What is the difference between the treatment of significant figures in addition and multiplication?

In 1 hour there are 3600 seconds. By what conversion \(\mathrm{fac}-\) tor would you multiply 250 seconds to convert it to hours? By what conversion factor would you multiply 3.84 hours to convert it to seconds?

If you were to convert the measured length \(4.165 \mathrm{ft}\) to yards by multiplying by the conversion factor \((1 \mathrm{yd} / 3 \mathrm{ft})\), how many significant figures should the answer contain? Why?

Write the equation that defines density. Identify the symbols in the equation.

Compare density and specific gravity. What is the difference between the two? When would specific gravity be used?

Give four sets of units for density. What mathematical operation must be carried out to convert the density into specific gravity for these four sets of units?

Silver has a density of \(10.5 \mathrm{~g} \mathrm{~cm}^{-3}\). Express this as an equivalence between mass and volume for silver. Write two conversion factors that can be formed from this equivalence for use in calculations.

Determine whether each of the following is a physical or chemical change, and explain your reasoning. (a) Copper conducts electricity. (b) Gallium metal melts in your hand. (c) Bread turns brown in a toaster. (d) Wine turns to vinegar. (e) Cement hardens.

Determine whether each of the following is a physical or chemical change, and explain your reasoning. (a) Iron rusts. (b) Kernels of corn are heated to make popcorn. (c) Molten copper is mixed with molten gold to make an alloy. (d) Heavy cream is churned to make butter. (e) Water vapor cools into water.

At room temperature, what is the state of each of the following? If necessary, look up the information in a reference source. (a) hydrogen (c) nitrogen (b) aluminum (d) mercury

At room temperature, determine the appropriate phase for each of the following substances. (Look up the substance in data tables if needed.) (a) potassium chloride (c) methane (b) carbon dioxide (d) sucrose

What number should replace the question mark in each of the following? (a) \(1 \mathrm{~cm}=? \mathrm{~m}\) (d) \(1 \mathrm{dm}=? \mathrm{~m}\) (b) \(1 \mathrm{~km}=? \mathrm{~m}\) (e) \(1 \mathrm{~g}=? \mathrm{~kg}\) (c) \(1 \mathrm{~m}=? \mathrm{pm}\) (f) \(1 \mathrm{cg}=? \mathrm{~g}\)

What numbers should replace the question marks below? (a) \(1 \mathrm{nm}=? \mathrm{~m}\) (d) \(1 \mathrm{Mg}=? \mathrm{~g}\) (b) \(1 \mu \mathrm{g}=? \mathrm{~g}\) (e) \(1 \mathrm{mg}=? \mathrm{~g}\) (c) \(1 \mathrm{~kg}=? \mathrm{~g}\) (f) \(1 \mathrm{dg}=? \mathrm{~g}\)

Perform the following conversions. (a) \(57^{\circ} \mathrm{C}\) to \({ }^{\circ} \mathrm{F}\) (c) \(378 \mathrm{~K}\) to \({ }^{\circ} \mathrm{C}\) (b) \(-25.5^{\circ} \mathrm{F}\) to \({ }^{\circ} \mathrm{C}\) (d) \(-31^{\circ} \mathrm{C}\) to \(\mathrm{K}\)

Perform the following conversions. (a) \(98^{\circ} \mathrm{F}\) to \({ }^{\circ} \mathrm{C}\) (c) \(299 \mathrm{~K}\) to \({ }^{\circ} \mathrm{C}\) (b) \(-55^{\circ} \mathrm{C}\) to \({ }^{\circ} \mathrm{F}\) (d) \(40.0^{\circ} \mathrm{C}\) to \(\mathrm{K}\)

The temperature of the core of the sun is estimated to be about 15.7 million \(\mathrm{K}\). What is this temperature in \({ }^{\circ} \mathrm{C}\) and \({ }^{\circ} \mathrm{F}\) ?

Natural gas is mostly methane, a substance that boils at a temperature of \(109 \mathrm{~K}\). What is its boiling point in \({ }^{\circ} \mathrm{C}\) and \({ }^{\circ} \mathrm{F}\) ?

A healthy dog has a temperature ranging from \(37.8^{\circ} \mathrm{C}\) to \(39.2^{\circ} \mathrm{C}\). Is a dog with a temperature of \(103.5{ }^{\circ} \mathrm{F}\) within the normal range?

In South America, the warmest recorded temperature of \(120.0{ }^{\circ} \mathrm{F}\) was in Rivadavia, Argentina. Was Death Valley's record temperature of \(56.7^{\circ} \mathrm{C}\) warmer or colder than the temperature in South America?

How many significant figures do the following measured quantities have? (a) \(37.53 \mathrm{~cm}\) (d) \(0.00024 \mathrm{~kg}\) (b) \(37.240 \mathrm{~cm}\) (e) \(2400 \mathrm{~mL}\) (c) \(202.0 \mathrm{~g}\)

How many significant figures do the following measured quantities have? (a) \(0.0230 \mathrm{~g}\) (d) \(614.00 \mathrm{mg}\) (b) \(105.303 \mathrm{~m}\) (e) \(10 \mathrm{~L}\) (c) \(0.007 \mathrm{~kg}\)

Perform the following arithmetic and round off the answers to the correct number of significant figures. Include the correct units with the answers. (a) \(0.0023 \mathrm{~m} \times 315 \mathrm{~m}\) (b) \(84.25 \mathrm{~kg}-0.01075 \mathrm{~kg}\) (c) \((184.45 \mathrm{~g}-94.45 \mathrm{~g}) /(31.4 \mathrm{~mL}-9.9 \mathrm{~mL})\) (d) \((23.4 \mathrm{~g}+102.4 \mathrm{~g}+0.003 \mathrm{~g}) /(6.478 \mathrm{~mL})\) (e) \((313.44 \mathrm{~cm}-209.1 \mathrm{~cm}) \times 8.2234 \mathrm{~cm}\)

Perform the following arithmetic and round off the answers to the correct number of significant figures. Include the correct units with the answers. (a) \(3.58 \mathrm{~g} / 1.739 \mathrm{~mL}\) (b) \(4.02 \mathrm{~mL}+0.001 \mathrm{~mL}\) (c) \((22.4 \mathrm{~g}-8.3 \mathrm{~g}) /(1.142 \mathrm{~mL}-0.002 \mathrm{~mL})\) (d) \((1.345 \mathrm{~g}+0.022 \mathrm{~g}) /(13.36 \mathrm{~mL}-8.4115 \mathrm{~mL})\) (e) \((74.335 \mathrm{~m}-74.332 \mathrm{~m}) /(4.75 \mathrm{~s} \times 1.114 \mathrm{~s})\)

Perform the following conversions. (a) \(32.0 \mathrm{dm} / \mathrm{s}\) to \(\mathrm{km} / \mathrm{hr}\) (d) \(137.5 \mathrm{~mL}\) to \(\mathrm{L}\) (b) \(8.2 \mathrm{mg} / \mathrm{mL}\) to \(\mu \mathrm{g} / \mathrm{L}\) (e) \(0.025 \mathrm{~L}\) to \(\mathrm{mL}\) (c) \(75.3 \mathrm{mg}\) to \(\mathrm{kg}\) (f) \(342 \mathrm{pm}^{2}\) to \(\mathrm{dm}^{2}\)

Perform the following conversions. (a) \(8.4 \mathrm{ft}^{2}\) to \(\mathrm{cm}^{2}\) (c) \(231 \mathrm{ft}^{3}\) to \(\mathrm{cm}^{3}\) (b) \(223 \mathrm{mi}^{2}\) to \(\mathrm{km}^{2}\)

Perform the following conversions. (a) \(2.4 \mathrm{yd}^{2}\) to \(\mathrm{m}^{2}\) (c) \(9.1 \mathrm{ft}^{3}\) to \(\mathrm{L}\) (b) \(8.3 \mathrm{in} .^{2}\) to \(\mathrm{mm}^{2}\)

The human stomach can expand to hold up to 4.2 quarts of food. A pistachio nut has a volume of about \(0.9 \mathrm{~mL}\). Use this information to estimate the maximum number of pistachios that can be eaten in one sitting.

In the movie Cool Hand Luke (1967), Luke wagers that he can eat 50 eggs in one hour. The prisoners and guards bet against him, saying, "Fifty eggs gotta weigh a good six pounds. A man's gut can't hold that." A peeled, chewed chicken egg has a volume of approximately \(53 \mathrm{~mL}\). If Luke's stomach has a volume of 4.2 quarts, does he have any chance of winning the bet?

The winds in a hurricane can reach almost 200 miles per hour. What is this speed in meters per second? (Assume three significant figures.)