Exam 1. Spring 2012/13 CHE 140 Section: 5701 & total points Date: Mon. Feb. 11 & Tue. Feb. 12, 2013

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1 + 80 points Exam 1 Spring 2012/13 Name: CHE 140 Section: 5701 & total points Date: Mon. Feb. 11 & Tue. Feb. 12, 2013 Directions: Answer the following questions completely. For multiple choice questions, circle the one best answer unless noted otherwise. If the question is a calculation, be sure to show all your work (including all units) for full credit. If you do not show your work, you will receive zero points and be very sad. If you have actually read these instructions circle your name for three-quarters points. The symbols to the left of each number indicate the chapter-concept arealetter that the question is testing over. The last page of this exam has a periodic table which you may rip off to use. 1. (2.5 points) Answer the following short answer or fill in the blank questions. a. What two things must you do to get out of having to take the final exam? b. The lowest homework assignment(s) will be dropped this semester. c. What is your instructor s name (first or last)? d. Arriving more than minutes late is considered tardy. e. What happens to homework submitted after the due date? 1-II-a 1-II-b 2. (2.25 points) Put biology, chemistry, and physics on the appropriate description of the predominant focus of study. a. The study of matter is b. The study of life is c. The study of motion is 3. (4.5 points) Label the following as either a chemical (C) or not chemical (N). a. sunlight c. wool e. paper b. oatmeal d. love f. dirt P-II-c P-III-a 1-II-c 1-III-a 4. (1.5 points) True or false? a. Theories develop when experiments prove that a given hypothesis is correct. b. Employing scientific information to develop new material to benefit society is an example of technology. 5. (1.5 points) Multiple choice: The first step in the scientific method is a. using technology. b. making observations. c. forming a hypothesis. d. doing experiments. e. proposing a theory. CHE 140 Exam 1 S13.docx Page 1 of 6

2 1-III-a 6. (3 points) Answer the following true or false questions. a. In the scientific method, a hypothesis must be changed if data or observations are collected that don t match it. b. Scientists believe that all natural phenomenons can be explained. c. A theory develops when performed experiments support the original hypothesis. d. Theories can never be proven, but they can be disproven. 1-IV-a,b 7. (4.5 points) Complete the following equalities, correctly. a. 1 nl = L c. 1 J = kj e. 1 ml = L b. 1 Mm = m d. 1 µs = s f. 1 m = cm 1-V-a 1-VI-a 8. (4.5 points) Complete the table below: number written out 5,102,000, number in scientific notation number of sig figs 4 1-VI-a,c,d,e 9. (6 points) Give the answer to the following problems (you do not have to show any work). Make sure your answers have the correct number of significant figures when asked (you may have to write in scientific notation so significant figures are certain). Answer from calculator Answer with correct sig figs a = b. 6 ( )= c. = d. = 6.47( ) 1-VI-a,b,c,e 1-VIII-b 10. (3 points) On Friday, February 15, 2013 an asteroid named 2012 DA14 will pass within 17,000 miles of Earth, close enough to hit some of our satellites. The gravity on this asteroid is that of Earth s. So, if an object has a weight of 100 kg on Earth, what is its mass on the asteroid? Briefly explain your answer. CHE 140 Exam 1 S13.docx Page 2 of 6

3 1-IV-a,b 1-VI-a,b,c,d,e 1-VII-a,b 11. (5 points) modified homework 1.87: In Mexico, avocados are 48 pesos per kilogram. a. What two conversion factors can we write from the following equality showing the exchange rate: pesos = 1 dollar? b. What is the cost in dollars of an avocado that weighs 0.52 lb? Note that 1 lb = kg. You must use dimensional analysis to get full credit; let your units help you! 1-IV-a,b 1-VI-a,b,c,d,e 1-VII-a,b 1-VIII-a 12. (4 points) Modified Homework 1.93: The water level in a graduated cylinder initially at ml rises to ml after a piece of lead is submerged. What is the mass in grams of the lead if its density is g/ml? 1-IV-a,b 1-VI-a,b,c,d,e 1-VII-a,b 1-VIII-a 1-VI-a,d 2-IV-d 13. (3.5 points) Multiple choice: Diamonds have a density of 3.52 g/ml. What is the volume in cm 3 of a diamond with a mass of 15.1 g? Show your work for partial credit considerations. a cm 3 b cm 3 c cm 3 d. 4.3 cm 3 e. 53 cm (5.5 points) Please complete the following temperature conversions. Be sure your conversion factor goes to at least two decimals! a. Convert ºC to K. c. Convert K to ºC. b. Convert ºC to K. d. Convert K to ºC. 1-VI-a,b,c,e 1-VIII-b 15. (3 points) On Friday, February 15, 2013 an asteroid named 2012 DA14 will pass within 17,000 miles of Earth, close enough to hit some of our satellites. The gravity on this asteroid is that of Earth s. So, if an object has a mass of 100 kg on Earth, what is its weight on the asteroid? Briefly explain your answer. CHE 140 Exam 1 S13.docx Page 3 of 6

4 2-II-b 2-II-c 16. (3 points) Indicate whether each statement describes potential or kinetic energy. a. an earthquake b. the calories in a candy bar c. falling snowflake d. tightly wound spring 17. (2 points) You go to a buffet and fill your bowl of soup from the large pot. a. Which has more heat, the pot or your bowl? b. Which has the higher temperature, the pot or your bowl? 1-IV-a 1-VI-a,c,d,e 1-VII-b 2-II-c 2-III-a,b 18. (4.5 points) Multiple choice: If 46.1 grams of ethanol, CH 3 CH 2 OH, at 22.0ºC absorbs 1.45 kj of heat, what is the final temperature of the ethanol? The specific heat of ethanol is 2.44 J/g ºC. Hint: q = mass specific heat T may be useful! a. 9.1ºC b. 22.0ºC c. 34.9ºC d. 47.0ºC e. 616ºC 1-IV-a 1-VI-a,c,d,e 1-VII-b 2-II-c 2-III-a,b 19. (5 points) modified homework 2.40a: How many kj of energy is given off by one cup of popcorn if it produces enough energy to change the temperature of 1,250 g of water from 25.5 ºC to 50.8ºC? The specific heat of water is 1.00 cal/gºc. Hint: q = mass specific heat T may be useful! 2-IV-a,b,c 20. (7.5 points) Classify each of the following as a/an element, compound, homogeneous mixture or heterogeneous mixture. a. baking soda f. ruby b. gasoline c. graphite in pencils d. ice e. ice-cream float g. helium in balloons h. noodle soup i. vinegar j. frosted flakes 2-IV-a,b,c 21. (3.75 points) In the previous question, circle the letters for all of the pure substances. Just circle the letter for the part. For instance, if part a is a pure substance, circle the letter a. CHE 140 Exam 1 S13.docx Page 4 of 6

5 1-VIII-a 2-IV-d 2-V-a 2-V-a 2-V-a,b,c 22. (5.25 points) To answer the following questions, use the pictures below. The circles in the boxes represent the submicroscopic pieces of a particular compound that is sealed in the box. Each box is a different temperature. a. What state of matter is in box A: B: C: b. What process happens if we go A B C from the contents of box A to B? from box B to C? c. In which box is at the highest temperature? d. In which box does the substance have the highest amount of density? 23. (4.5 points) From Concept Check 2.3: Identify the state(s) of matter described by the substance in each of the following. a. No change in volume when placed in a different container. b. Has an especially low density. c. Shape depends on the container. d. It has a definite shape and volume. 24. (5 points) modified homework 2.81: The melting point of carbon tetrachloride is 23ºC, and its boiling point is 77º. Sketch a heating curve for chloroform on the graph below and then answer the following questions. a. What is the state of chloroform T (ºC) at 50ºC? at 20ºC? at 90ºC? b. What would we see happening at 23ºC? 100 heat added c. At what temperature(s) will both solid and liquid be present? 2-V-d 25. (4.5 points) Identify whether the following are physical or chemical changes. a. water fills a glass b. a chocolate bar melts on a hot day c. hydrogen peroxide bubbles when put on a cut d. apple slices brown when exposed to air e. fluorine explodes in the presence of hydrogen f. spaghetti gets soft when put into water CHE 140 Exam 1 S13.docx Page 5 of 6 The End! You made it! Remember to check your work.

6 CHE 140 Exam 1 S13.docx Page 6 of 6 VIIIA 2 He Ne Ar Kr Xe Rn (222) 118 Uuo (294) VIIA 9 F Cl Br I At (210) VIA 8 O S Se Te Po (209) 116 Uuh (293) 71 Lu Lr (262) VA 7 N P As Sb Bi Uup (288) 70 Yb No (259) IVA 6 C Si Ge Sn Pb Uuq (289) 69 Tm Md (258) IIIA 5 B Al Ga In Tl Uut (284) 68 Er Fm (257) IIB 30 Zn Cd Hg Uub (285) 67 Ho Es (252) IB 29 Cu Ag Au Rg (280) 66 Dy Cf (251) 28 Ni Pd Pt Ds (281) 65 Tb Bk (247) VIIIB 27 Co Rh Ir Mt (276) 64 Gd Cm (247) 26 Fe Ru Os Hs (270) 63 Eu Am (243) VIIB 25 Mn Tc (98) 75 Re Bh (272) 62 Sm Pu (244) VIB 24 Cr Mo W Sg (271) 61 Pm (145) 93 Np (237) VB 23 V Nb Ta Db (268) 60 Nd U IVB 22 Ti Zr Hf Rf (267) 59 Pr Pa IIIB 21 Sc Y La Ac (227) 58 Ce Th IIA 4 Be Mg Ca Sr Ba Ra (226) *varies by sample origin IA 1 H Li 6.941* 11 Na K Rb Cs Fr (223) Table based on information obtained from on 2/20/09.