CHEMISTRY 100

EXAM 1a&b/ Fall 2000- 4 Oct ‘00 (both blue & white- a mistake)

Name_______________________ x is the correct answer
<sup>1. Radioactive dating of artifacts by C-14
a. relies on tree rings for calibration
b. can give inconclusive results when the tested material is contaminated
c. depends on the neutrons emitted by the sun
xd. all above

2. The amount of material needed for a nuclear explosion is called the
xa. critical mass b. kiloton c. megaton d. transmutation

3. Given an isotope with a half life of 3 seconds and an initial amount of 1000g, how much will remain after 9 sec?
a. 1000g b. 500g c. 250g xd. 125 g e. 62.5g</sup>

4. Science differs from technology in that
xa. science offers explanations of phenomena, technology typically does not offer explanations
b. science is not falsifiable
c. science is authoritative
d. science is about recipes and how-to information, technology is not

5. An hypothesis is
a. an experiment b. tentative c. explanatory xd. b&c

6. Experiments are
a. explanations x b. tests c. authoritative statements d. declarations by politicians

7. All information that is scientific information is considered to be
a. tentative b. testable c. conclusive forever xd. a&b

8. Theories
xa. are tentative b. are not questioned once established c. are not falsifiable d. b&c

9. Mass
a. and weight are always the same
b. is not changeable (except in extreme circumstances such as nuclear reactions)
c. is measured in grams
xd. b&c

10. The density of a 50 gram object that has a volume of 25 mL is
a. 2 b. 0.g gram/mL x c. 2 g/mL d. 1250 g/mL e. 1250

11. In order to find the density of an irregular object, one can use water displacement in some circumstances. A student had a graduated cylinder into which she placed 35 mL.
She then put the object into the water. It sank to the bottom of the water. The water level now read 46 mL. Some data that we can glean from the activities of the student are (is):
xa. the object is more dense than water
b. the object has a volume of 46 mL
c. given only the above data we can calculate density
d. all above are true


12. Heat is measured in
a. calories b. degrees Celsius c. Joules d. all above xe. a& c above ONLY

13. The main difference between temperature and heat is
a. actually there is no difference
xb. heat requires knowledge of quantity of matter, temperature does not
c. heat is measured in kilograms, temperature in liters
d. all above

14. If you measure length you need to use the following units
a. seconds
b. degrees Celsius
c. liters
xd. meters
e. kilograms

15. To convert milliliters (mL) to liters (L) one has the conversion factor 1000 mL = 1 L.
The correct factor label or dimensional analysis set-up to convert 50 mL to L is:
a. x= 1000 mL x 50 mL/ 1L

b. x= 50mL x 1000mL/ 1L

xc. x= 50 mL x 1L/1000mL

d. x= 1L x 1000mL/50 mL


16. A scientific law is
a. an explanation
xb. an invariant correlation between sets of facts
c. not tentative
d. not testable

17. A compound would be
xa. CO
b. Co
c. Li
d. Mg

18. An element would be
a. S₈ b. Al c. P₄ d. NO xe. a,b,c above



19. Given the reaction O_{2 +} 2H_{2 =} 2H₂O
32 g 4g 36 g
The masses shown leave no leftover O or H. All H & O are converted to water.
a. using 64 g of O should double the mass of water produced
b. adding 8 g of H should double the mass of water produced
xc. adding both 64g of O and 8g of H should double the mass of water produced
d. none above

20. Vitamin C (ascorbic acid) produced by oranges is
a. different in composition from vitamin C produced in a factory
xb. identical to the vitamin C produced in a factory
c. much better because it is natural
d. has a different formula from vitamin C produced in a factory

21. Compounds that seem to illustrate the law of multiple proportions are
a. H₂O₂ H₂O b. CO CO₂ c. NaOCl NaOBr xd. a&b only

22. If a reaction occurs with the definite proportions shown below:
C + O₂ = CO₂
12g 32g

Then we can expect _____ of product.
xa. 44g b. 38 g c. 32 g d. 88 g


23. In experiment 1 we used CuSO₄, NaCl, H₂O, and Al. Since we did not exclude air, we also involved N, CO₂, and Ar.
a. SO<sub>2 could not have been the gas
xb. rust, Fe(OH)3 could not be produced
c. Cu could not be the brown product
d. H could not be the gas

24. Chemical reactions
a. involve the creation of new atoms
b. involve the loss of some atoms
c. involve rearrangement of atoms- no loss or gain
d. involve new substances being formed
xe. c&d above

25. The electron configuration for the ground state of oxygen, atomic number 8 is</sub>
a. 1s²2s²2s²2p³3s¹ b. 1s¹2s²2p⁵ xc. 1s²2s²2p⁴ d. 1s²2s¹2p<sup>5

26. The number of protons in oxygen atoms is: (atomic #= 8, atomic mass=16)
a. 16 xb. 8 c. 4 d. 24

27. Li is in the group of elements called
a. nonmetals b. transition metals xc. alkali metals d. halogens

28. Elements (by atomic number) that we expect to react in a similar way are
xa. 11, 19, 37 b. 11, 12, 13 c. 15, 16, 18 d. 84, 85, 86

29. There are at least two isotopes of oxygen, O-16 and O-18
a. These isotopes do not react alike in a chemical reaction
b. these isotopes have different numbers of electrons
c. these isotopes have different numbers of protons
xd. these isotopes have different numbers of neutrons

30. The radiation type that goes farthest in air is
a. alpha b. beta xc. gamma d. all go the same distance</sup>

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