Exam 1
Spring 2012/13 Name: ____________________________
CHE 140 Section: 5701 & 5702
100 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 area-letter 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?
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 _____ b. oatmeal _____ c. wool _____ d. love _____ e. paper _____ f. dirt 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.
points
80
+
1-II-b P-II-c P-III-a 1-II-a 1-II-c 1-III-aCHE 140 Exam 1 S13.docx Page 2 of 6
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. 7. (4.5 points) Complete the following equalities, correctly.
a. 1 nL = ________ L b. 1 Mm = ________ m c. 1 J = ________ kJ d. 1 µs = ________ s e. 1 mL = ________ L f. 1 m = ________ cm 8. (4.5 points) Complete the table below:
number written out 5,102,000,000 379.160 0. 000007080 number in scientific notation 1.52×108 – 7.60×10–4 number of sig figs 4
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. 169.539 ÷ 54.69 = _______________________ ______________________ b. ×
(
×)
= × −6 8 10 4 . 12 47 . 6 10 01 . 22 _______________________ ______________________ c. = × × 44 57 10 4613 . 10 10 1012 . 8 _______________________ ______________________ d. = × × − ) 10 4 . 12 ( 47 . 6 10 01 . 22 6 8 _______________________ ______________________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 2.2×10–17 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.
1-IV-a,b 1-V-a,b 1-VI-a,c,d,e 1-VI-a,b,c,e 1-VIII-b 1-III-a 1-V-a 1-VI-a
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: 12.77 pesos = 1 dollar?
b. What is the cost in dollars of an avocado that weighs 0.52 lb? Note that 1 lb = 0.454 kg.
You must use dimensional analysis to get full credit; let your units help you!
12. (4 points) Modified Homework 1.93: The water level in a graduated cylinder initially at 215.0 mL rises to 284.2 mL after a piece of lead is submerged. What is the mass in grams of the lead if its density is 11.30 g/mL?
13.(3.5 points) Multiple choice: Diamonds have a density of 3.52 g/mL. What is the volume in cm3 of a diamond with a mass of 15.1 g? Show your work for partial credit considerations. a. 53.2 cm3
b. 4.29 cm3 c. 0.233 cm3 d. 4.3 cm3 e. 53 cm3
14.(5.5 points) Please complete the following temperature conversions. Be sure your conversion factor goes to at least two decimals!
a. Convert 68.04 ºC to K.
b. Convert –143.10 ºC to K.
c. Convert 288.88 K to ºC.
d. Convert 29.00 K to ºC.
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 2.2×10–17 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.
1-VI-a,d 2-IV-d 1-IV-a,b 1-V-a,b 1-VI-a,b,c,d,e 1-VII-a,b 1-IV-a,b 1-V-a,b 1-VI-a,b,c,d,e 1-VII-a,b 1-VIII-a 1-IV-a,b 1-V-a,b 1-VI-a,b,c,d,e 1-VII-a,b 1-VIII-a 1-VI-a,b,c,e 1-VIII-b
CHE 140 Exam 1 S13.docx Page 4 of 6
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? _______________ 18.(4.5 points) Multiple choice: If 46.1 grams of ethanol, CH3CH2OH, 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
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!
20.(7.5 points) Classify each of the following as a/an element, compound, homogeneous mixture or heterogeneous mixture. a. baking soda ______________ b. gasoline ______________ c. graphite in pencils ______________ d. ice ______________ e. ice-cream float ______________ f. ruby ______________ g. helium in balloons ______________ h. noodle soup ______________ i. vinegar ______________ j. frosted flakes ______________ 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”.
2-II-b 1-IV-a 1-V-a,b 1-VI-a,c,d,e 1-VII-b 2-II-c 2-III-a,b 2-IV-a,b,c 2-IV-a,b,c 2-II-c 1-IV-a 1-V-a,b 1-VI-a,c,d,e 1-VII-b 2-II-c 2-III-a,b
CHE 140 Exam 1 S13.docx Page 5 of 6
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
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
at –50ºC?
at 20ºC? at 90ºC?
b. What would we see happening at –23ºC?
c. At what temperature(s) will
both solid and liquid be present? 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
2-V-a 2-V-d 1-VIII-a 2-IV-d 2-V-a A B C 100 –60 –100 T ( ºC ) 60 –20 20 heat added 2-V-a,b,c
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