Name: ______KEY______Leedy, Spring 2013
CHM 130 Exam 1 – Chapters 1, PSS, 2, 3, 4, and 5 Directions. There is only one best answer for multiple-choice questions. For calculations you must show all your work and the proper units if applicable. Pay attention to significant digits in answers! Good Luck.
1. (4 pts) Which of the following is one of the steps in the scientific method? a. perform an experiment and collect data b. analyze experimental data and propose a hypothesis c. test a hypothesis and state a theory or law d. all of the above
2. (4 pts) Circle all of the EXACT numbers in this list: 5 meters 2 fingers 3 grams 8 cats
3. (12 pts) Measure the length of Object A and Object B using Rulers I, II, and III in the image below.
Object A: Ruler I: __6.79 cm____ Ruler II: __6.7 cm_____ Ruler III: __6.5 cm___
Object B: Ruler I: __4.49 cm___ Ruler II: __4.3 cm____ Ruler III: __4.5 cm____
4. (4 pts) How many significant figures are in the following numbers? a. 680.0 ___4____ c. 680 ____2____ b. 6080 ___3_____ d. 0.00680 ___3_____
5. (3 pts) Round the following numbers to three significant figures. a. 145,459,000 _____145,000,000______page 1 of 6 b. 1716.0 _____1.72 x 104______c. 0.015681 ___0.0157______
6. (4 pts) Write the following numbers in scientific notation. a. 21,310 = ____2.131 x 104______c. 0.00002010 = ___2.010 x 10-5______
b. 2,103,000 = __2.103 x 106______d. 195,500,000,000 = __1.955 x 1011______
7. (4 pts) Solve the following math problems. Be sure your answer has the correct number of significant figures. a. 12.59 * 8.453 = __106.4____ c. 15.962 + 1.49654 = __17.459______
4.2 x 1014 b. 139.4 - 0.514 = ___138.9___ d. = __1.8 x 106______2.34789 x 108
8. (4 pts) If a solution is made by combining 2.54 g of sodium chloride and 75.00 g of water, what percent of the solution is sodium chloride?
(Part / whole) * 100 = percent (2.54 g / (2.54 + 75.00)) * 100 = 3.28 %
9. (3 pts) If a penny has a mass of 2.507 g and is 97.5% zinc, what is the mass of zinc in the coin?
(x / 2.507 g) * 100 = 97.5% x = 2.44 g
10. (6 pts) Circle all of the following that are correct unit conversions:
1 km 1 cm 1000 cm 1 dm 1000 mm 1000 m
1000 m 100 m 1 km 10 cm 1 m 1 km
11. (3 pts) When my friends moved to France, they had to order their deli lunch meat in grams. How many grams would you ask for if you wanted ¾ of a pound (0.75 pounds) of ham? 1 pound = 453.6 grams
0.75 lb * (453.6 g / 1 lb) = 3.4 x 102 g
12. (4 pts) Anna got an injection of 2.4 g (micrograms) of vitamin B12 to boost energy. How many mg is this? a. 2.4 x 10-6 mg b. 2.4 x 10-3 mg c. 2.4 mg d. 2.4 x 103 mg
13. (3 pts) You have to sit and listen to me for 1.25 hours (75 minutes) each class meeting. How many seconds are you being tortured/entertained in my class?
1.25 hours * (3600 sec / 1 hr) = 4.50 x 103 sec
14. (4 pts) The Sears Tower in Chicago is 1454 feet tall. How high is this in meters?
1454 ft * (12 in. / 1 ft) * (2.54 cm / 1 in.) * (1 m / 100 cm) = 443.2 meters page 2 of 6 15. (4 pts) How many fluid ounces (fl. oz.) are in a 2.5 gallon container? 4 qt = 1 gal; 32 fl oz = 1 qt
2.5 gal * (4 qt / 1 gal) * (32 fl. oz. / 1 qt) = 320 fl. oz.
16. (4 pts) Thomas’s beer cooler measures 68 cm by 48 cm by 42 cm. What is the volume of his cooler? a. 140,000 cm3 b. 160 cm3 c. 137088 cm
17. (5 pts) What is the volume of a 5.00 g pure aluminum cylinder if its density is 2.70 g/cm3?
D = m / V V = m / D = 5.00 g / 2.70 g/cm3 V = 1.85 cm3
18. (4 pts) Which of the following would float on honey (d=1.5 g/mL) but sink in hexane (d=0.65 g/mL)? a. a penny, d = 4.3 g/mL c. crouton, d = 0.53 g/mL e. wood chip, d = 0.73 g/mL b. marble, d = 7.8 g/mL d. whipped cream, d = 0.25 g/mL
19. (6 pts) A collection of glass beads has a mass of 29.33 g. the beads were transferred to a graduated cylinder containing 113.5 mL of water. The volume of the water plus beads was 125.2 mL. Calculate the density of the glass beads.
V = 125.2 mL – 113.5 mL = 11.7 mL D = m / V = 29.33 g / 11.7 mL = 2.51 g/mL
20. (5 pts) The melting point of iron is 1535oC. What is this in Fahrenheit? What is this in Kelvin?
oF = (1.8 x oC) + 32 = (1.8 x 1535oC) + 32 = 2795oF; K = oC + 273 = 1535oC + 273 = 1808 K
21. (4 pts) You step out outside in the middle of the night in winter in Montana.
a. What loses heat, your foot or the ground? _____foot______
b. What gains heat? ____ground______
22. (4 pts) Which of the following terms refers to the flow of energy from an object at a higher temperature to an object at a lower temperature? a. calorie b. heat c. specific heat d. temperature
23. (2 pts) Which state of matter generally has the highest density? ____solid______
1. (5 pts) For each of the following statements, identify whether it refers to the properties of a solid (S), liquid (L), or a gas (G). Circle the appropriate letter or letters for each statement (more than one letter might be chosen).
a. S L G Particles have constant/definite volume. b. S L G Particles will assume shape and volume of container. page 3 of 6 c. S L G Particles only vibrate in place, do not move relative to each other. d. S L G Particles are not easily compressed. e. S L G Particles move about and slide past each other rather closely.
2. (6 pts) For each image below, identify if it shows a pure substance or a mixture. Then identify what type or types of particles are shown (atoms, elements, compounds).
Pure or mixture? Mixture Pure Pure
Types of Elements (molecules) Elements (molecules) Compounds particles?
3. (4 pts) Identify whether the following terms describe a physical or a chemical change: a. vaporization: _physical__ c. combustion: ___ chemical ___ b. precipitation: __chemical___ d. sublimation: ___ physical ____
4. (10 pts) Complete the following table: Metal, Physical state Diatomic Atomic Element Symbol Nonmetal, or at 25oC? Element? Number Semimetal s, l, or g? Yes or No carbon C 6 Semi-metal S No fluorine F 9 Nonmetal G Yes
5. (3 pts) How many of each type of atom are in citric acid (H3C6H5O7)?
H: 8 C: 6 O: 7
6. (5 pts) Which of the following is/are chemical properties? Circle all that apply. a. density b. color c. reactivity with water d. boiling point e. flammability
7. (4 pts) In the procedure shown below, a calcium chloride solution is mixed with a sodium sulfate solution to create the products shown. Which of the following is illustrated by this activity?
page 4 of 6 a. The law of definite proportions/composition b. The law of gravity c. The law of conservation of mass d. Periodic Law
8. (9 pts) True or False: Circle “T” if a statement below is true; circle “F” if a statement below is false. a. T F Bohr discovered the nucleus of an atom. b. T F Protons are negatively charged particles in an atom. c. T F The nucleus of an atom contains the protons and neutrons of an atom. d. T F Rutherford proposed the plum pudding (or chocolate chip ice cream) model of the atom (in that it contains negatively charged particles). e. T F An atom’s atomic mass is the same as its number of protons. f. T F Isotopes of an atom differ by the number of neutrons in the nucleus. g. T F Light diffracted by elements contains all colors in the visible spectrum of light. h. T F The 1st level in the periodic table contains 2 sublevels. i. T F Any orbital can hold at most 2 electrons.
9. (3 pts) Use the image to the right to answer the following questions. Which wave has:
a. photons with the highest energy? __ii__
b. the longest wavelength? __iii__
c. the lowest frequency? __iii__
10. (4 pts) Using atomic notation, indicate the isotope having 11 p+, 12 n0, and 11 e-. page 5 of 6 12 23 23 12 23 a. 11 Na b. 11Na c. 12 Na d. 11 Mg e. 12 Mg
11. (4 pts) Boron occurs naturally as 10B and 11B. Which isotope is more abundant? (Hint: Refer to the Periodic Table.) a. boron-5 b. boron-6 c. boron-10 d. boron-11 e. none of the above
12. (5 pts) a. Write electron configurations for phosphorus: __1s2 2s2 2p6 3s2 3p3______b. How many valence electrons does phosphorus have? ___5____ c. When it reacts to form an ion, what charge will it have? ___-3______d. With which noble gas will the ion be isoelectronic? ___Ar______
13. (4 pts) What is the name of the family of elements in Group IIA/2? a. alkali metals b. alkaline earth metals c. halogens d. noble gases e. none of the above
14. (4 pts) Which of the following is an alkali metal in the 4th period? a. Li b. Na c. K d. Rb e. all of the above
15. (4 pts) Which of the following elements has the smallest atomic radius? a. F b. Cl c. Br d. O e. S
16. (4 pts) Which of the following is a general trend in the periodic table for the metallic character of the elements? a. increases from left to right, increases from bottom to top b. increases from left to right, decreases from bottom to top c. decreases from left to right, increases from bottom to top d. decreases from left to right, decreases from bottom to top e. none of the above
17. (5 pts) Which of the following elements will have similar chemical reactive properties to Mg? Circle all that apply. a. Sr b. P c. Na d. Ba e. Ne
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