Chemistry Chapter One Questions

1. Many laboratories use 25 *C as a standard temperature. What is this temperature in kelvins?

298 K

5. A marathon distance race covers a distance of 42.195 kn. What is this distance in meters? In miles?

42,195 m; 26.219 miles

17. You are on a diet that calls for eating no more than 1200 Cal/day. What is this energy in joules?

5.0 x 10^6 J

13. Ethylene glycol, C2H6O2, is an ingredient of automobile antifreeze. Its density is 1.11 g/cm3 at 20 *C. If you need 500 mL of this liquid, what mass of the compound, in grams, is required?

555g

4. Give the symbol for each of the following elements: a. Silver b. Aluminum c. Plutonium d. Tin e. Technetium f. Krypton

As Al Pu Sn Tc Kr

3. Give the symbol for each of the following elements: a. Barium b. Titanium c. Chromium d. Lead e. Arsenic f. Zinc

Ba Ti Cr Pb As Zn

1. Give the name of each of the following elements: a. C b. K c. Cl d. P e. Mg f. Ni

Carbon Potassium Chlorine Phosphorous Magnesium Nickel

5. In each of the following pairs, decide which is an element and which is a compound. a. Na or NaCl b. Sugar or carbon c. Gold or gold chloride

E: Na C:NaCl E: carbon C: Sugar E: gold C: gold chloride

6. In each of the following pairs, decide which is an element and which is a compound. a. Pt(NH3)2Cl2 or Pt b. Copper or copper (II) oxide c. Silicon or sand

E:Pt C: Pt(NH3)2Cl2 E:copper C: copper (II) Oxide E: silicon C: sand

35. You can figure out whether a solid floats or sinks if you know its density and the density of the liquid. In which of the liquids listed below will high-density polyethylene (HDPE) float? (HDPE, a common plastic, has a density of 0.97 g/cm3. It does not dissolve in any of these liquids.) Substance Density (g/cm3) Properties, Uses *Ethylene glycol 1.1088 Toxic; major component of automobile antifreeze *Water 0.9997 Ethanol 0.7893 Alcohol in alcoholic beverages *Methanol 0.7914 Toxic; gasoline additive to prevent gas line freezing *Acetic acid 1.0492 Component of vinegar *Glycerol 1.2613 Solvent used in home care products

HDPE will float in ethylene glycol, water, acetic acid, and glycerol.

2. Give the name of each of the following elements: a. Mn b. Cu c. Na d. Br e. Xe f. Fe

Manganese Copper Sodium Bromine Xenon Iron

11. The flashlight in the photo does not use batteries. Instead, you move a lever, which turns a geared mechanism and finally results in light from the bulb. What type of energy is used to move the lever? What types of energy are produced?

Mechanical energy is used to move the lever, which in turn moves gears. The device produces electrical energy and radiant energy.

17. Which observations below describe chemical properties? a. Sugar is soluble in water b. Water boils at 100*C c. Ultraviolet light converts O3 (ozone) to O2 (oxygen) d. Ice is less dense than water

Observation c is a chemical property

33. Solve the following equation for the unknown value, T. a. (4.184) (244) (T-292.0) + (0.449) (88.5) (T - 369.0) = 0

T = 295

You have a 250.0 mL graduated cylinder containing some water. You drop three marbles with a total mass of 95.2g into the water. What is the average density of a marble? (see image for more details 43c.)

The volume of the marbles is 99 mL - 61 mL = 38 mL. This yields a density of 2.5 g/cm^3.

3. Make the following temperature conversions: a. 16C → ?K b. 370 K → c. 40 C →

a. 289 K b. 97 *C c. 310 K (3.1 x 10^2 K)

23. Express the following numbers in exponential or scientific notation, and give the number of significant figures in each. a. 0.054 g b. 5462 g c. 0.000792 g d. 1600 mL

a. 5.4 x 10^-2 g, two sig figs b. 5.462 x 10^3g, four sig figs c. 7.92 x 10^-4g, three sig figs d. 1.6 x 10^3 mL, two sig figs

25. Carry out the following operations. Provide the answer with the correct number of significant figures. a. (1.52) (6.21 X 10-3) b. (6.217 X 103) - (5.23 X 102) c. (6.217 X103) / (5.23 X 102) d. (0.0546) (16.0000) [7.779/55.85]

a. 9.44 x 10^-3 b. 5694 c. 11.9 d. 0.122

13. Determine which of the following represent potential energy and which represent kinetic energy. a. Thermal b. Gravitational c. Chemical d. Electrostatic

a. Kinetic energy b. Potential energy c. Potential energy d. Potential energy

21. You and your lab partner are asked to determine the density of an aluminum bar. The mass is known accurately (to four significant figures). You use a simple matric ruler to measure its dimensions and obtain the results for Method A. Your partner uses a precision micrometer and obtains the results for Method B. Method A (g/cm3) 22. 2.3 2.7 2.4 Method B (g/cm3) 2.703 2.701 2.705 5.811

a. Method A with all data included: average = 2.4 g/cm^3 Method B with al data included: average = 3.480 g/cm^3 For B, the 5.811 g/cm^3 data point can be excluded because it is more than twice as large as all other points for Method B. Using only the first three points, average = 2.703 g/cm^3 b. Method A: error = 0.3 g/cm^3 or about 10% Method B: error = 0.001 g/cm^3 or about 0.04% c. Method A: standard deviation = 0.2 g/cm^3 Method B (excluding all data points): standard deviation = 1.554 g/cm^3 Method B (excluding the 5.811 g/cm^3 data point): standard deviation = 0.002 g/cm^3 d. Method B's average value is both more precise and more accurate so long as the 5.811 g/cm^3 data point is excluded

8. In each case, decide if the change is a chemical or physical change. a. A cup of household bleach changes the color of your favorite T-Shirt from purple to pink. b. Water vapor in your exhaled breath condenses in the air on a cold day. c. Plants use carbon dioxide from the air to make sugar. d. Butter melts when placed in the Sun.

a. Physical b. Chemical c. Chemical d. Physical

9. Which part of the description of a compound or element refers to its physical properties and which to its chemical properties? a. The colorless liquid ethanol burns in air. b. The shiny metal aluminum reacts readily with orange-red bromine.

a. Physical (colorless liquid) and chemical (burns in air) b. Physical (shiny metal, orange-red) and chemical (reacts with bromine)

16. Iron pyrite (fool's gold, page 11) has a shiny golden metallic appearance. Crystals are often in the form of perfect cubes. A cube 0.40 cm on each side a. Which of these observations are qualitative and which are quantitative? b. Which of the observations are extensive and which are intensive?

a. Qualitative : shiny gols, metallic, perfect cubes Quantitative: 0.04 cm per side b. Extensive: 0.40 am per slide Intensive: color, cubes shape

15. A piece of turquoise is a blue-green solid; it has a density of 2.65 g/cm3 and a mass of 2.5 g. a. Which of these observations are qualitative and which are quantitative? b. Which of the observations are extensive and which are intensive? c. What is the volume of the piece of turquoise?

a. Qualitative: blue-green color, solid, physical state Quantitative: density = 2.65 g/cm3 and mass = 2.5g b. Density, physical state, and color are intensive properties, whereas mass is an extensive property. c. Volume = 0.94 cm^3

14. Determine whether kinetic energy is being converted to potential energy, or vise versa, in the following processes. a. Water cascades downward into a waterfall. b. A player kicks a football c. An electric current is generated by a chemical reaction in a battery. d. Water boils when heated on a gas stove.

a. kinetic to potenial b. potential to kinetic c. kinetic to potential d. kinetic to potential

29. Categorize each of the following as an element, a compound, or a mixture. a. Sterling silver b. Carbonated mineral water c. Tungsten d. Aspirin

a. mixture b. mixture c. element d. compound

10. Which part of the description of a compound or element refers to its physical properties and which to its chemical properties? a. Calcium carbonate is white solid with a density of 2.71 g/cm3. It reacts readily with an acid to produce gaseous carbon dioxide. b. Gray, powdered zinc metal reacts with purple iodine to give a white compound.

a. physical (Calcium, white solid, density, gaseous) and chemical (reacts readily with acid)

7. In each case, decide if the underlined property is a physical or chemical property a. The color of elemental bromine is orange-red. b. Iron turns to rust in the presence of air and water. c. Hydrogen can explode when ignited in air. (Fig. 1.15) d. The density of titanium metal is 4.5 g/cm3. e. Tin metal melts at 505 K. f. Chlorophyll, a plant pigment is green.

a. physical property b. Chemical property c. Chemical d. physical e. physical f. physical

29. (See graph for details pg 43b) Use the graph below to answer the following questions. a. Derive the equation for the straight line, y = mx + b. b. What is the value of y when x = 6.0?

a. y = -4.00x +20.00 b. y = -4.00

18. Which observation below describes chemical properties? a. Sodium metal reacts violently with water b. The combustion od octane (a compound in gasoline) gives CO2 and H2O. c. Chlorine is a green gas d. Heat is required to melt ice

a. yes b. yes c. no d. no

15. You can identify a metal by carefully determining its density (d). An unknown piece of metal, with a mass of 2.361 g, is 2.35 cm long, 1.34 cm wide and 1.05 mm thick. Which of the following is the element? a. Nickel, d = 8.91 g/cm3 b. Titanium, d = 4.50 g/cm3 c. zinc, d = 7.14 g/cm3 d. Tin, d= 7.23 g/cm3

c. zinc

23. Identify the following as either physical changes or chemical changes. a. Dry ice (solid CO2) sublimes (converts directly from solid to gaseous CO2) b. Mercury's density decreases as the temperature increases. c. Energy is given off as heat when natural (mostly methane, CH4) burns d. NaCl dissolves in water

physical changes: a, b, d Chemical changes: c

12. A solar panel is pictured in the photo. When light shines on the panel, it generates an electric current that can be used to recharge the batteries in an electric car. What types of energy are involved in this setup?

thermal, electrical...not sure all kinds, going to check odd answers in library soon!