Matterisanything...

CHE 121 Problem Paper 1
1. Which of the following is not a part of the scientific method:
(A) Perform an experiment and record observations.
(B) Develop a hypothesis to explain data.
(C) Eliminate data that conflicts with hypothesis.
(D) Perform additional experiments to test hypothesis.
2. Define matter
Matter is anything that has mass and occupies space. Matter is the material of the universe.
3. The amount of matter in an object is described by what quantity?
Its mass
4. Explain the difference between chemical and physical changes.
Chemical changes result in the formation of new substances, physical changes do not.
5. Identify each of the following statements as either true or false.
(A) An atom may be defined as the limit of physical subdivision. F
(B) The particles that make up molecules are called atoms. T
(C) In chemical reactions atoms are rearranged, separated, combined
or destroyed. F
(D) Molecules comprised of two atoms are called diatomic molecules. T
6. Molecules containing atoms of the same type are called what?
Elements or homoatomic molecules.
7. If when a pure substance is heated it decomposes into two fragments that
have different chemical and physical properties from each other and the original substance then the original substance must have been?
(A) homoatomic
(B) heteroatomic
8. Using the abbreviations given identify each of the following as either
homogeneous (HM) or heterogeneous (HT) mixtures.
(A) Mouthwash HM
(B) Chunky peanut butter HT
(C) Normal urine HM
(D) Blood HM
(E) Liquid eye drops HM
(F) Petroleum jelly (Vaseline) HM
(G) Sand HT
(H) A salad HT
9. Identify the following statements as true of false.
(A) The pure substances in mixtures can be separated by physical
methods. T
(B) Elements contain two or more types of atoms. F
(C) Compounds contain three or less types of atoms. F
(D) Elements contain only one type of atom. T
10. Given that the formula relating the Celsius and Kelvin temperature scales is:
o C = K – 273
where o C indicates the temperature in units of Celsius degrees and K indicates the temperature in units of kelvin.
If the temperature of a sample increased by 32.5 o C how many kelvin units would the temperature of the sample have increased by?
32.5 Kelvin units.
11. Perform the following conversions.
(A) Express 1400 millimeters in meters
(B) Express 100 joules in kilojoules
(C) Express 139 seconds in days
(D) 13 mL as liters
(A)
m 1.4mm 1400mm
10001m m
1 mm 1000=×= (B)
j 0.1 j 100j
1000kj 1kj
1 j 1000=×=
(C)
days 3-10 x 1.61 hours 2-10 x 3.86hours
24day 1 day
1 hours 24hours 2-10 x 3.86 minutes 2.32minutes
60hour 1hour
1 minutes 60minutes 2.3
2 s 139s
60minute 1minute
1 s 60=×==×==×= (D)
L 2-10 1.3 mL 13mL
1000L 1L
1 mL 1000×=×=
12. What is a characteristic of a chemical change?
A) a substance melts or freezes B) a material evaporates
C) neither of the above
D) both of the above
13. The scientific method tries to determine the nature of the problem.
A) True B) False
14. Burning is an example of a physical change. A) True B) False
15. What is the abbreviation for liters, a unit of volume?
L
16. Mass is always measured in grams.
A) True B) False
17. There are 10,000 meters in a kilometer.
A) True B) False
18. How many milliliters are in 0.468 L?
mL 468 L 468.0L
1mL 1000L
1 mL 1000=×=
19. How many centimeters are there in 2.54 in.?
cm 6.45 in 2.54 in
0.394 cm 1in
0.394 cm 1=×=
20. How many grams are there in a sample of salt weighing 1,908 mg?
g 1.908 mg 1908 mg
1000 g 1g
1 mg 000 1=×=
21. How many milliliters are there in 13.500 L?
mL 13500 L 13.500 L
1 mL 000 1L
1 mL 000 1=×=
22. What kind of change is the burning of wood to charcoal?
Chemical
23. To change a measurement from milliliters to centimeters, what kind of conversion is required?
It is not possible to perform this conversion.
24. When metal rusts, what sort of change has occurred?
Chemical
25. When snow melts, is this a physical or a chemical change?
Physical
26. What is the SI unit of time?
Seconds
27. Without using scientific notation express the following in milligrams (you may need to use Tables 1.2 and 1.3 in your text).
A) 2 pounds B) 3 ng
C) 0.5 kg D) 6 ounces E) 16 grams (A)
mg 910000 g 0 91 g 1mg 1000g
1 mg 1000g 910 kg 0.91
kg 1g 1000kg
1 1000g kg 0.91 pound 2
pound 2.20kg 1kg
1 pound 2.20=×==×==×=
(B)
mg 0.000002 g 020.00000000
g 1mg 1000g
1 mg 1000g 020.00000000 ng
2 ng 1000000000g 1g
1 ng 1000000000=×==×= (C)
mg 500000 g 005 g 1mg 1000g
1 mg 1000g 500 kg 5.0
kg 1g 000 1kg
1 g 1000=×==×=
(D)
mg 171428 g 4.711
g 1mg 1000g
1 mg 1000g 171.4 ounces 6
ounces 0.035g 1g
1 ounces 0.035=×==×=
(E)
mg 16000 g 61
g 1mg 1000g
1 mg 1000=×=
28. Write the answers from question 27 in scientific notation.
(A) 9.1 x 105 mg
(B) 2.0 x 10-6 mg
(C) 5.0 x 105 mg
(D) 1.7 x 105 mg
(E) 1.6 x 104 mg
29. Give the symbol and multiplier for the following prefixes.
A) micro B) mega
C) centi D) deci E) pico
(A) µ, 10-6
(B) M, 106
(C) c, 100
(D) d, 10
(E) p, 10-12
30. Round the following numbers to 3 significant figures.
A) 1.247 B) 1.244 C) 1.345 D) 21.76
(A) 1.25
(B) 1.24
(C) 1.34
(D) 21.8
31. Do the following operations and express your answers to the correct
number of significant figures:
A) (3.5 x 104)(2.00 x 10-16)
B) 2.768 – 4.1
C) 3.5 x (3.61 x 102)
D) (4.7 x 10-2) ÷ 3
E) 1000 x (2.1 x 10-17)
F) 120.679 + 32.1 – 6.23
(A) 7.0 x 10-12
(B) -1.3
(C) 1.3 x 103
(D) 2 x 10-2
(E) 2.1 x 10-14
(F) 146.5。