GENERAL CHEMISTRY I
CHEM 1311.001
EXAM 1
Friday June 12, 1998

1. A tentative explanation of natural phenomena is a(n)
a) theoryb) hypothesisc) law
d) experimente) observation
2. A concise statement, or mathematical equation about natural phenomena is a(n)
a) theoryb) hypothesisc) law
d) experimente) observation
3. A tested explanation of natural phenomena is a(n)
a) theoryb) hypothesisc) law
d) experimente) observation
4. An observation of natural phenomena carried out in a controlled manner so that the results are reproducible and rational conclusions can be obtained is called
a) theoryb) hypothesisc) law
d) experimente) observation
5. A law usually

a) applies only to one or two specific cases

b) applies to a broad variety of cases

6. A scientific law is
a) never wrongb) sometimes wrongc) usually wrong
d) always wrong
7. Which can we be more confident is correct, a theory or hypothesis?
a) theoryb) hypothesis
8. The process by which knowledge about the natural world is acquired, tested and refined was represented in class by a "flowchart". What was this general process called?
a) planned inquiryb) trial and errorc) systematic study
d) reflective analysise) the scientific method
9. A chemist measured the volume of a water sample with a graduated cylinder and reported the reading as 11.05 mL. How many significant figures are there in the number 11.05 as used in this context?
a) 2b) 3c) 4d) indeterminant (can't tell)
e) infinite (exact)
10. An electrical engineer measured the length of a telephone cable and reported its length to be 8.00 m. How many significant figures are there in the number 8.00 as used in this context?
a) 1b) 2c) 3d) indeterminant (can't tell)
e) infinite (exact)
11. A small piece of zinc metal was weighed on an analytical balance. The mass of the metal was found to be 0.0068 g. How many significant figures are there in the number 0.0068 as used in this context?
a) 2b) 3c) 4d) 5
e) indeterminant (can't tell)
12. A small bead of copper was weighed on an analytical balance and found to have a mass of 0.0300 g. How many significant figures are there in the number 0.0300 as used in this context?
a) 1b) 2c) 3d) 4e) 5
13. This summer, the number of students enrolled in Mr. Robinson's lab is 20. How many significant figures are there in the number 20 as used in this context?
a) 1b) 2c) indeterminant (can't tell)
d) infinite (exact)
14. By appropriate measurements, astronomers can estimate interplanetary distances. It has been reported that the distance from the earth to the sun is 93,000,000 miles. How many significant figures are there in the number 93,000,000 as used in this context?
a) 1b) 2c) 8d) indeterminate (can't tell)
e) infinite (exact)
15. Density is the ratio of a substance's mass to it's volume -- that is, d = m / V. To determine the density of an unknown liquid, a chemist measured out a 5.00 mL sample of the liquid and with a graduated pipet, and then weighed the sample on an analytical balance. The mass of the 5.00 mL liquid sample was found to be 3.9450 g. What is the density of the liquid, expressed to the correct number of significant figures?
a) 0.8 g / mLb) 0.79 g / mLc) 0.789 g / mL
d) 0.7890 g / mLe) 0.7890 g / mL
16. The area of a rectangular figure is calculated by multiplying its length by its width. That is, A = L x W. If a rectangular figure has a length of 12.7 cm and a width of 4.2 cm, what is the area of the figure, expressed to the correct number of significant figures?
a) 5 x 101 cm2b) 53 cm2c) 53.3 cm2
d) 53.34 cm2e) 53.340 cm2
17. A short piece of string was measured with a ruler that allowed lengths to be estimated to +/- 0.01 cm. The length of the short piece of string was reported to be 1.75 cm. A longer piece of string was then measured using a ruler that only allowed lengths to be estimated to +/- 0.1 cm. The length of the longer piece of string was reported to be 11.6 cm. What is the combined length of the two pieces of string expressed to the correct number of significant figures?
a) 1 x 101 cmb) 13 cmc) 13.4 cm
d) 13.35 cme) 13.350 cm
18. A student wanted to determine the mass of a water sample. The student started by weighing an empty beaker on an analytical balance (which gives mass readings to +/- 0.0001 g). The beaker was found to have a mass of 42.7198 g. Then the water sample was added to the beaker and the beaker was weighed on a top-loading balance that only gave mass readings to +/- 0.01 g. The beaker with the water sample was found to have a mass of 54.24 g. What is the mass of water in the beaker, expressed to the correct number of significant figures?
a) 12 gb) 11.5 gc) 11.52 g
d) 11.520 ge) 11.5202 g
19. In class, we learned about "certain digits" and "uncertain digits". How many uncertain digits should be included in any measured or calculated number (when expressed as the final answer to a problem)?
a) noneb) onec) two
d) as many as you want
20. In the United States, gasoline is sold by the gallon, but in most other countries, it is sold by the liter. The relationship between these two units of measure is that a gallon is 3.785 liters. (In equation form 1 gal = 3.785 L) If your car's gasoline tank holds 15.0 gallons, how many liters does it hold?
a) 12.7 Lb) 25.4 Lc) 42.6 Ld) 56.8 Le) 71.5 L
21. The speed limit on many Texas highways is 55 mi / hr. What would this speed limit be if expressed in km / hr? Note that 1 km = 0.6215 mi. Hint: Since the time unit is hours in each case, you only need to convert the distance. In one hour, a car traveling the speed limit would go 55 miles. How many kilometers would it go in that same hour?
a) 35 km / hrb) 53 km / hrc) 64 km / hrd) 72 km / hre) 88 km / hr
22. What is the mass, in kilograms, of a person who weighes 209 pounds? Note that 1 kg = 2.205 lb.
a) 42.9 kgb) 68.2 kgc) 94.8 kgd) 121 kge) 148 kg
23. If an atom has 8 protons and 10 neutrons in its nucleus

a) it must be an atom of oxygen

b) it must be an atom of neon

c) it must be an atom of argon

d) it can not be determined what element it is, since the number of electrons was not specified

24. If an atom has an atomic number of 6 and a mass number of 14, how many neutrons does it have?
a) 6b) 8c) 14d) 20e) 22
25. The law of definite proportions states that all samples of a _______________ must have the same percentage composition by mass.
a) compoundb) mixture
26. What is the formula of sodium sulfide?
a) NaSb) Na2Sc) NaS2d) Na2S3e) Na3S2
27. What is the formula of aluminum oxide?
a) AlOb) Al2Oc) AlO2d) Al2O3e) Al3O2
28. What is the formula of magnesium chloride?
a) MgClb) Mg2Clc) MgCl2d) Mg2Cl3e) Mg3Cl2
29. What is the formula of calcium oxide?
a) CaOb) Ca2Oc) CaO2d) Ca2O3e) Ca3O2
30. What is the formula of magnesium nitride?
a) MgNb) Mg2Nc) MgN2d) Mg2N3e) Mg3N2
31. What is the formula of aluminum phosphate?
a) AlPO4b) Al2PO4c) Al(PO4)2d) Al2(PO4)3e) Al3(PO4)2
32. What is the formula of calcium nitrate?
a) CaNO3b) Ca2NO3c) Ca(NO3)2d) Ca2(NO3)3e) Ca3(NO3)2
33. What is the formula of potassium carbonate?
a) KCO3b) K2CO3c) K(CO3)2d) K2(CO3)3e) K3(CO3)2
34. What is the formula of copper(II) chloride?
a) CuClb) Cu2Clc) CuCl2d) Cu2Cl3e) Cu3Cl2
35. What is the formula of copper(I) oxide?
a) CuOb) Cu2Oc) CuO2d) Cu2O3e) Cu3O2
36. What is the formula of cupric sulfate? Hint: You already know what the two charges are for the copper ion. See problems 34 and 35.
a) CuSO4b) Cu2SO4c) Cu(SO4)2d) Cu2(SO4)3e) Cu3(SO4)2
37. Which of the following would be a valid name for Cu3PO4? Hint: You already know what the two charges are for the copper ion. See problems 34 and 35.
a) cuprous phosphateb) cupric phosphate
c) copper(III) phosphated) both a and c
e) both b and c
38. The names of all binary acids begin with
a) hydrob) hyperc) hypod) per
e) none of these
39. What is the name of H2CO3?
a) carbonous acidb) carbonic acidc) hydrocarbonic acid
d) hypocarbonous acide) percarbonic acid
40. What is the name of H2SO3?
a) sulfurous acidb) sulfuric acidc) hydrosulfuric acid
d) hyposulfurous acide) persulfuric acid
*** END OF TEST ***


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