Chapter 1

Explain how you could experimentally determine whether the outside temperature is higher or lower than \(0^{\circ}\) \(\left(32^{\circ} \mathrm{F}\right)\)without using a thermometer.

Identify each of the following statements as being most similar to a hypothesis, a law, or a theory. Explain your reasoning. (a) Falling barometric pressure precedes the onset of bad weather. (b) All life on earth has evolved from a common, primitive organism through the process of natural selection. (c) My truck's gas mileage has dropped significantly, probably because it's due for a tune-up.

Identify each of the following statements as being most similar to a hypothesis, a law, or a theory. Explain your reasoning. (a) The pressure of a sample of gas is directly proportional to the temperature of the gas. (b) Matter consists of tiny particles that can combine in specific ratios to form substances with specific properties. (c) At a higher temperature, solids (such as salt or sugar) will dissolve better in water.

Identify each of the underlined items as a part of either the macroscopic domain, the microscopic domain, or the symbolic domain of chemistry. For any in the symbolic domain, indicate whether they are symbols for a macroscopic or a microscopic feature. (a) The mass of a lead pipe is 14 lb. (b) The mass of a certain chlorine atom is 35 amu. (c) A bottle with a label that reads Al contains aluminum metal. (d) Al is the symbol for an aluminum atom.

According to one theory, the pressure of a gas increases as its volume decreases because the molecules in the gas have to move a shorter distance to hit the walls of the container. Does this theory follow a macroscopic or microscopic description of chemical behavior? Explain your answer.

The amount of heat required to melt 2 lbs of ice is twice the amount of heat required to melt 1 lb of ice. Is this observation a macroscopic or microscopic description of chemical behavior? Explain your answer.

Why is an object's mass, rather than its weight, used to indicate the amount of matter it contains?

What properties distinguish solids from liquids? Liquids from gases? Solids from gases?

How does a heterogeneous mixture differ from a homogeneous mixture? How are they similar?

How does a homogeneous mixture differ from a pure substance? How are they similar?

How does an element differ from a compound? How are they similar?

How do molecules of elements and molecules of compounds differ? In what ways are they similar?

How does an atom differ from a molecule? In what ways are they similar?

Classify each of the following as an element, a compound, or a mixture: (a) copper (b) water (c) nitrogen (d) sulfur (e) air (f) sucrose (g) a substance composed of molecules each of which contains two iodine atoms (h) gasoline

Classify each of the following as an element, a compound, or a mixture: (a) iron (b) oxygen (c) mercury oxide (d) pancake syrup (e) carbon dioxide (f) a substance composed of molecules each of which contains one hydrogen atom and one chlorine atom (g) baking soda (h) baking powder

A sulfur atom and a sulfur molecule are not identical. What is the difference?

How are the molecules in oxygen gas, the molecules in hydrogen gas, and water molecules similar? How do they differ?

Why are astronauts in space said to be "weightless," but not "massless"?

Matter is everywhere around us. Make a list by name of fifteen different kinds of matter that you encounter every day. Your list should include (and label at least one example of each) the following: a solid, a liquid, a gas, an element, a compound, a homogenous mixture, a heterogeneous mixture, and a pure substance.

When elemental iron corrodes it combines with oxygen in the air to ultimately form red brown iron(III) oxide called rust. (a) If a shiny iron nail with an initial mass of \(23.2 \mathrm{g}\) is weighed after being coated in a layer of rust, would you expect the mass to have increased, decreased, or remained the same? Explain. (b) If the mass of the iron nail increases to \(24.1 \mathrm{g}\), what mass of oxygen combined with the iron?

As stated in the text, convincing examples that demonstrate the law of conservation of matter outside of the laboratory are few and far between. Indicate whether the mass would increase, decrease, or stay the same for the following scenarios where chemical reactions take place: (a) Exactly one pound of bread dough is placed in a baking tin. The dough is cooked in an oven at \(350^{\circ} \mathrm{F}\) releasing a wonderful aroma of freshly baked bread during the cooking process. Is the mass of the baked loaf less than, greater than, or the same as the one pound of original dough? Explain. (b) When magnesium burns in air a white flaky ash of magnesium oxide is produced. Is the mass of magnesium oxide less than, greater than, or the same as the original piece of magnesium? Explain. (c) Antoine Lavoisier, the French scientist credited with first stating the law of conservation of matter, heated a mixture of tin and air in a sealed flask to produce tin oxide. Did the mass of the sealed flask and contents decrease, increase, or remain the same after the heating?

Yeast converts glucose to ethanol and carbon dioxide during anaerobic fermentation as depicted in the simple chemical equation here: glucose \(\longrightarrow\) ethanol \(+\) carbon dioxide (a) If \(200.0 \mathrm{g}\) of glucose is fully converted, what will be the total mass of ethanol and carbon dioxide produced? (b) If the fermentation is carried out in an open container, would you expect the mass of the container and contents after fermentation to be less than, greater than, or the same as the mass of the container and contents before fermentation? Explain. (c) If 97.7 g of carbon dioxide is produced, what mass of ethanol is produced?

Classify each of the following changes as physical or chemical: (a) condensation of steam (b) burning of gasoline (c) souring of milk (d) dissolving of sugar in water (e) melting of gold

Classify each of the following changes as physical or chemical: (a) coal burning (b) ice melting (c) mixing chocolate syrup with milk (d) explosion of a firecracker (e) magnetizing of a screwdriver

The volume of a sample of oxygen gas changed from \(10 \mathrm{mL}\) to \(11 \mathrm{mL}\) as the temperature changed. Is this a chemical or physical change?

A 2.0-liter volume of hydrogen gas combined with 1.0 liter of oxygen gas to produce 2.0 liters of water vapor. Does oxygen undergo a chemical or physical change?

Explain the difference between extensive properties and intensive properties.

Identify the following properties as either extensive or intensive. (a) volume (b) temperature (c) humidity (d) heat (e) boiling point

The density (d) of a substance is an intensive property that is defined as the ratio of its mass (m) to its volume (V). density \(=\frac{\text { mass }}{\text { volume }} \quad d=\frac{m}{V}\)

Is one liter about an ounce, a pint, a quart, or a gallon?

Is a meter about an inch, a foot, a yard, or a mile?

Indicate the SI base units or derived units that are appropriate for the following measurements: (a) the length of a marathon race (26 miles 385 yards) (b) the mass of an automobile (c) the volume of a swimming pool (d) the speed of an airplane (e) the density of gold (f) the area of a football field (g) the maximum temperature at the South Pole on April 1,1913

Indicate the SI base units or derived units that are appropriate for the following measurements: (a) the mass of the moon (b) the distance from Dallas to Oklahoma City (c) the speed of sound (d) the density of air (e) the temperature at which alcohol boils (f) the area of the state of Delaware (g) the volume of a flu shot or a measles vaccination

Give the name and symbol of the prefixes used with SI units to indicate multiplication by the following exact quantities. (a) \(10^{3}\) (b) \(10^{-2}\) (c) \(0.1\) (d) \(10^{-3}\) (e) \(1,000,000\) (f) \(0.000001\)

Give the name of the prefix and the quantity indicated by the following symbols that are used with SI base units. (a) c (b) d (c) G (d) k (e) m (f) n (g) p (h) T

A large piece of jewelry has a mass of 132.6 g. A graduated cylinder initially contains 48.6 mL water. When the jewelry is submerged in the graduated cylinder, the total volume increases to \(61.2 \mathrm{mL}\). (a) Determine the density of this piece of jewelry. (b) Assuming that the jewelry is made from only one substance, what substance is it likely to be? Explain.

Express each of the following numbers in scientific notation with correct significant figures: (a) 711.0 (b) 0.239 (c) 90743 (d) 134.2 (e) 0.05499 (f) 10000.0 (g) 0.000000738592

Express each of the following numbers in exponential notation with correct significant figures: (a) 704 (b) 0.03344 (c) 547.9 (d) 22086 (e) 1000.00 (f) 0.0000000651 (g) 0.007157

Indicate whether each of the following can be determined exactly or must be measured with some degree of uncertainty: (a) the number of seconds in an hour (b) the number of pages in this book (c) the number of grams in your weight (d) the number of grams in 3 kilograms (e) the volume of water you drink in one day (f) the distance from San Francisco to Kansas City

How many significant figures are contained in each of the following measurements? (a) 38.7 g (b) \(2 \times 10^{18} \mathrm{m}\) (c) 3,486,002 kg (d) \(9.74150 \times 10^{-4} \mathrm{J}\) (e) \(0.0613 \mathrm{cm}^{3}\) (f) \(17.0 \mathrm{kg}\) (g) 0.01400 g/mL

How many significant figures are contained in each of the following measurements? (a) \(53 \mathrm{cm}\) (b) \(2.05 \times 10^{8} \mathrm{m}\) (c) 86,002 J (d) \(9.740 \times 10^{4} \mathrm{m} / \mathrm{s}\) (e) \(10.0613 \mathrm{m}^{3}\) (f) \(0.17 \mathrm{g} / \mathrm{mL}\) (g) 0.88400 s

The following quantities were reported on the labels of commercial products. Determine the number of significant figures in each. (a) 0.0055 g active ingredients (b) 12 tablets (c) \(3 \%\) hydrogen peroxide (d) 5.5 ounces (e) 473 mL (f) 1.75\% bismuth (g) 0.001\% phosphoric acid (h) 99.80\% inert ingredients

Round off each of the following numbers to two significant figures: (a) 0.436 (b) 9.000 (c) 27.2 (d) 135 (e) \(1.497 \times 10^{-3}\) (f) 0.445

Round off each of the following numbers to two significant figures: (a) 517 (b) 86.3 (c) \(6.382 \times 10^{3}\) (d) 5.0008 (e) 22.497 (f) 0.885

Perform the following calculations and report each answer with the correct number of significant figures. $$(a) 628 \times 342$$ $$\text { (b) }\left(5.63 \times 10^{2}\right) \times\left(7.4 \times 10^{3}\right)$$ $$\text { (c) } \frac{28.0}{13.483}$$ $$\text { (d) } 8119 \times 0.000023$$ $$\text { (e) } 14.98+27,340+84.7593$$ $$(f) 42.7+0.259$$

Perform the following calculations and report each answer with the correct number of significant figures. $$(a) 62.8 \times 34$$ $$\text { (b) } 0.147+0.0066+0.012$$ $$\text { (c) } 38 \times 95 \times 1.792$$ $$(d) 15-0.15-0.6155$$ $$\text { (e) } 8.78 \times\left(\frac{0.0500}{0.478}\right)$$ $$(f) 140+7.68+0.014$$ $$(g) 28.7-0.0483$$ $$\text { (h) } \frac{(88.5-87.57)}{45.13}$$

Write conversion factors (as ratios) for the number of: (a) yards in 1 meter (b) liters in 1 liquid quart (c) pounds in 1 kilogram

Write conversion factors (as ratios) for the number of: (a) kilometers in 1 mile (b) liters in 1 cubic foot (c) grams in 1 ounce

The label on a soft drink bottle gives the volume in two units: 2.0 \(\mathrm{L}\) and \(67.6 \mathrm{fl}\) oz. Use this information to derive a conversion factor between the English and metric units. How many significant figures can you justify in your conversion factor?

The label on a box of cereal gives the mass of cereal in two units: 978 grams and 34.5 oz. Use this information to find a conversion factor between the English and metric units. How many significant figures can you justify in your conversion factor?