APPLIED CHEMISTRY, MS. WACK
SCIENTIFIC MEASUREMENTS, HOMEWORK PACKET
DAY
1
9/14/11
2
3
4
5
6
7
8
9
10
11
12
13
CLASSWORK
Define Vocabulary Terms
HOMEWORK
Study for tomorrow’s vocabulary quiz
Vocabulary Quiz (20 Points)
Scientific Method/Parts of an Experiment
HW1: Worksheet A
Scientific Method
Begin to Design Experiment: “Bubbles”
Bubbles Lab (30 Points)
Daily Quiz
Uncertainty in Measurements
Accuracy/Precision
Percent Error
Measuring Activity (5 points)
Daily Quiz
Significant Figures
Daily Quiz
Scientific Notation
Daily Quiz
Base & Derived Units
Density
Temperature
Daily Quiz
Dimensional Analysis
All Homework and Extra Credit Due (50 Points)
Finish Daily Quiz (25 Points)
Density Pre-Lab
Density Lab
HW2: Worksheet B
Complete the design of your bubbles lab.
Finish Bubbles Lab
HW3: Worksheet C
Density Lab
Complete Lab
Study for Test
Density Lab Due (40 Points)
HW4: Worksheet D
HW5: Worksheet E
HW6: Worksheet F
HW7: Worksheet G
Finish Density Pre-Lab
Work on Lab
Review for Test
14
Tent. 10/4
Scientific Measurements Test (100 Points)
TOTAL POSSIBLE POINTS FOR CHAPTER 1: 270 + 20 POSSIBLE EXTRA CREDIT POINTS
HOMEWORK GRADES
A
50/50
B
45/50
C
40/50
D
35/50
F
30/50
NO GRADE
0/50
ALL HW COMPLETE
7/7 HW
6/7 HW COMPLETE
5/7 HW COMPLETE
4/7 HW COMPLETE
3/7 HW COMPLETE
LESS THAN 3/7 HW
COMPLETE
EXTRA CREDIT
6 Points: Ask Ms. Wack for the Article “Chefs as Chemists”. Answer the following
questions about the article:
1)
What are 2 hypotheses that may have been formed to lead to these chefs
discoveries?
2)
What is one experiment that may have been performed to lead to the chefs
discoveries?
-What would be the dependent and the independent
variables in this experiment?
-What would be the constant in this experiment?
-What would be the control in this experiment?
3)
What were two conclusions the chefs made?
5 Points: Worksheet I
4 Points: Worksheet J
5 Points: Worksheet K
WORKSHEET A
CHEMISTRY & THE SCIENTIFIC METHOD
A. Classify each step in the following application of the scientific method as an OBSERVATION, HYPOTHESIS, EXPERIMENT, or
THEORY.
1. An iron ball falls to Earth when you drop it.
________________________________________________________
2. Earth is a giant magnet.
________________________________________________________
3. An iron ball and a piece of wood are dropped at the same time from the same height._____________________________________
4. The iron ball and wood fall at the same rate.
________________________________________________________
5. The large mass of Earth causes it to exert the same gravitational attraction on any object, regardless of the object’s composition.
________________________________________________________
B. Propose one hypothesis for each of the following observations.
1. Hummingbirds have long beaks.
__________________________________________________________________________________________________
2. Moisture forms on the outside of a cold glass.
__________________________________________________________________________________________________
3. Ice cubes float.
__________________________________________________________________________________________________
4. There are fewer fish in the creek this year.
__________________________________________________________________________________________________
C. For the following experiments identify the independent variable, the dependent variable, the control and the constant(s).
1. You water 3 sunflower plants with salt water. Each plant receives a different concentration of salt solution. A fourth plant
receives pure water. After a 2 week period, the height is measured.
Independent Variable:____________________________
Dependent Variable:________________________
Control:_______________________________________
Constant(s):_______________________________
2. Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is left outside in
normal conditions. Height of the tree is measured once a week.
Independent Variable:____________________________
Dependent Variable:________________________
Control:_______________________________________
Constant(s):_______________________________
3. One tank of gold fish is fed the normal amount of food once a day, a second tank is fed twice a day, and a third tank four
times a day during a six week study. The fish’s weight is recorded daily.
Independent Variable:____________________________
Dependent Variable:________________________
Control:_______________________________________
Constant(s):_______________________________
4. Different rose bushes are grown in a greenhouse for 2 months. The number of flowers on each bush is counted at the
end of the experiment.
Independent Variable:____________________________
Dependent Variable:________________________
WORKSHEET B
SCIENTIFIC THEORY & EXPERIMENTS
MULTIPLE CHOICE
Write the letter of the correct answer on the line.
_____ 1. A student wants to test the hypothesis that plants need soil to grow. What is the independent variable of the experiment?
a. air temperature b. amount of water
c. amount of light
d. presence of soil
_____ 2. What does an experiment test?
a. a conclusion
b. a hypothesis
c. an observation
d. a control
_____ 3. Which of the following is an example of a scientific question?
a.
Does a slice of pizza have more fat than a serving of green beans?
b.
Does pizza taste better than green beans?
c.
Is pepperoni a better pizza topping than mushrooms?
d.
Are store brand green beans tastier than bran-name green beans?
_____ 4. A student uses a balance to find the mass of a lizard. Which method or process is the student using?
a. independent variable
b. conclusion
c. hypothesis
d. gathering data
_____ 5. Daniella records how much of a certain chemical dissolves in 100 grams of water at different temperatures. Her data are shown below.
0C/24 g
20C/36 g
40C/48 g
10C/30 g
30C/42 g
50C/54 g
What kind of data has Daniella recorded?
a. inference
b. conclusion
c. qualitative
d. quantitative
_____ 6. Which best describes a scientific law?
a.
a rule that uses experimental results and observations to describe a pattern in nature
b.
a scientific explanation of related observations that have been repeatedly tested and shown to be true over time
c.
a suggested answer to a scientific question
d.
a written account of the purpose of an investigation, the procedure followed and the results obtained
_____ 7. The density of an object is calculated by dividing the mass of the object by its volume. Which tools can be used to find the density of a bar
of silver?
a. beaker and pipette
b. pan balance and graduated beaker
c. beaker and metric ruler
d. triple-beam balance and metric ruler
_____ 8. The graph shows the relationship between the volume of a gas and its temperature when pressure is held constant. Which of the following
statements summarizes the data in the graph?
a.
As the temperature increases, the volume of the gas decreases due to an increase in the motion of gas particles
b.
As the temperature increases, the volume of the gas increases due to an increase in the motion of gas particles
c.
The volume of the gas is not affected by an increase in temperature
d.
The volume is affected by temperature only if the gas is hydrogen
WORKSHEET C
UNCERTAINTY IN MEASUREMENTS
A
B
C
1. Which of the above dartboards represents precision? __________________________________
2. Which of the above dartboards represents accuracy? __________________________________
3. Which of the above dartboards does represents neither precision nor accuracy?
______________________________
4. To the correct number of significant figures, what is the volume of the
liquid in the graduated cylinder to the left?
5. To the correct number of significant figures, what is the length of
the paper above the ruler to the left?
6. How many digits are estimated in a measurement?
7. Explain how a series of measurements can be precise without being accurate.
8. A student measures the boiling point of water to be 98C. What is his percent error?
WORKSHEET D
CALCULATING WITH SIGNIFICANT FIGURES
A. Round the following to the number of significant figures indicated in parentheses.
1) 8060 (3)
___________________________
4) 36.618 (3)
__________________________________
2) 599.99 (3)
___________________________
5) 0.08654 (2)
__________________________________
3) 2365.6 (4)
___________________________
6) 0.002345 (3) __________________________________
B. Perform the following operations expressing the answer in the correct number of significant figures and units.
1. 1.35 m x 2.467 m =
________________________________________________________________
2. 1035 m2  42 m =
________________________________________________________________
3. 12 cm x 0.031 cm x 7.969 cm =
________________________________________________________________
4. 55.46 g  28.9 g =
________________________________________________________________
5. 289 cg x
________________________________________________________________
1g=
100 cg
6. 1.152 mm x 0.215 mm x 0.032 mm =
________________________________________________________________
7. 5.23 m2  16.941 m =
________________________________________________________________
8. 6.419 g x 3.912 g x 7.0518 g x 0.00013 g
_______________________________________________________
C. Circle the correct answer.
1. Which of the following shows two significant figures?
a. 123000
b. 300
c. 0.001
d. 2.0 x 10-12
e. 8.70
d. 4
e. 5
d. 126.000
e. 201.0
d. 17
e. 6.0
2. How many significant figures are shown in the number 4.03 x 105?
a. 1
b. 2
c. 3
3. Which of the following numbers shows 4 significant figures?
a. 1800
b. 75.010
c. 0.009
4. Which of the following numbers shows 1 significant figure?
a. 60.0
b. 1.0 x 101
c. 700
WORKSHEET E
SCIENTIFIC NOTATION
A. Express the following measurements in scientific notation.
1. 453.32
___________________________
6. 1,000
___________________________
2. 0.0000421
___________________________
7. 0.00040
___________________________
3. 667000
___________________________
8. 0.01001
___________________________
4. 885326251
___________________________
9. 50
___________________________
5. 1,000,000.
___________________________
10. 0.0008
___________________________
B. Convert the following to standard notation.
1. 3.0 x 106
___________________________
4. 4.4 x 10-7
___________________________
2. 1.49 x 10-5
___________________________
5. 3.75 x 102
___________________________
6. 3.35 x 101
___________________________
3. 5.000102 x 103 ___________________________
C. Perform the following calculations using scientific notation. Make sure your answer has the correct number of significant figures.
1. (9.39 x 106) x (4.37 x 10-8) =
2. (5.12 x 103)  (8.61 x 104) =
3. (3.1 x 102) x (1.2 x 102) =
4. (1.0 x 109)  (2.5 x 10-3) =
5. (3.234 x 103) x
1
(5.0234 x 10-23)
=
WORKSHEET F
SI UNITS/DENSITY
A. Complete the Following Table
Measurement
Unit
Tool
Mass of a Rock
Your Body Temperature
Volume of a Plastic Block
Length of Your Classroom
How much water a tablespoon holds
How long between blinks of your eye
B. The table below gives the density of selected substances. Answer the following questions.
Substance
Density (g/mL)
Water (at 4C)
1.000
Hydrogen
0.00090
Carbon Dioxide
?
Gasoline
0.68
Copper
8.89
Silver
10.5
Mercury
13.595
Tungsten
19.3
1. Which of the substances listed in the table has the greatest density?_______________________________________________
2. Which of the substances listed in the table has the lowest density?________________________________________________
3. If you were given a milliliter of copper and a milliliter of silver, which would weigh more? Why?______________________________
____________________________________________________________________________________________________
4. Corks are used on fishing lines because they float. What can you say about the density of cork?____________________________
____________________________________________________________________________________________________
5. To complete the table, calculate the density for carbon dioxide if 250.0 mL of the gas has a mass of 0.4997 g.__________________
6. Suppose that 10 mL of each of the three liquids in the table—water, gasoline and mercury—were all placed in a test tube. The liquids do not mix with one
another. In the three layers that would be produced, which liquid would be on top, which in the middle and which on the bottom?____________________________
C. Complete the following temperature conversions.
K = C + 273
C = K -273
a) Convert -200C to Kelvin
b) Convert 355 K to Celsius
c) Convert 183.66C to Kelvin
d) Convert 100.23 Kelvin to Celsius
e) Convert 123C to Kelvin
f) Convert 355.0 K to Celsius
WORKSHEET G
DIMENSIONAL ANALYSIS/CONVERSIONS
1. How many L are there in 1000 mL?
2. Convert 83 cm into meters.
3. Convert 459 L into milliliters.
4. Express 1123 pg in nanograms.
5. Express 2.5 mm in micrometers.
6. Convert 1342 cs to seconds.
7. Which is the smaller mass, 285.0 cg or 23.78 dg? (Hint: Convert both to g first to compare.)
8. Calculate the number of kilometers there are in 105 meters.
9. An object has a mass of 89.00 grams. Express this mass in centigrams.
10. A very small object is found to have a length of 0.000344 meters. Express this length in micrometers.
WORKSHEET I
EXTRA CREDIT
1. The table below gives data on the number of gallons of water used in a condominium building and the amount of the
monthly water bill during 2008. Create a line graph for the data (may use computer or do by hand).
Water Use (Gallons)
Water Bill ($)
17 200
105.32
4100
32.01
1000
18.74
1205
19.67
1100
19.17
400
16.17
9500
63.64
8202
56.75
1400
20.45
5225
40.97
810
17.65
600
17.03
2. Draw a best fit line into the graph.
3. If a water main broke during the month of February due to a deep freeze, and the water usage in the building totaled
11,200 gallons, what would the bill amount to?
4. The water company sends the association a bill for $200, how much water did the building use? Should you argue about
the bill?
WORKSHEET J—EXTRA CREDIT
WRITE THE LETTER OF THE CORRECT ANSWER ON THE LINE.
_____ 1. A sample of an element has a mass of 34.261 grams and a volume of 3.8 cubic centimeters. To which number of significant figures should
the calculated density of the sample be expressed?
(A) 5
(B) 3
(C) 2
(D) 4
_____ 2. Which quantity of heat is equal to 200. joules?
(A) 20.0 kJ
(B) 0.200 kJ
(C) 2.00 kJ
(D) 0.0200 kJ
_____ 3. A large sample of solid calcium sulfate is crushed into smaller pieces for testing. Which two physical properties are the same for both the
large sample and one of the smaller pieces?
(A) mass and density
(B) mass and volume
(C) solubility and density
(D) solubility and volume
_____ 4. The table below shows mass and volume data for four samples of substances at 298 K and 1 atmosphere.
Which two samples could consist of the same substance?
Sample
Mass (g)
Volume (mL)
A
B
C
D
(A) A and B
30
40
45
90
(B) B and C
60
50
90
120
(C) A and C
(D) C and D
_____ 5. A student intended to make a salt solution with a concentration of 10.0 grams of solute per liter
of solution. When the student’s solution was analyzed, it was found to contain 8.90 grams of solute per liter of solution. What was the percent error in
the concentration of the solution?
(A) 1.10%
(B) 11.0%
(C) 8.90%
(D) 18.9%
_____ 6. A student calculates the density of an unknown solid. The mass is 10.04 grams, and the volume is
8.21 cubic centimeters. How many significant figures should appear in the final answer?
(A) 1
(B) 3
(C) 2
(D) 4
_____ 7. Horses kept in stables sometimes chew on wood. This can lead to damage to the mouth and digestive system. The graph above shows
the results of a study of a medication that prevents horses from chewing on wood. From the graph, what inference can be made about the
effectiveness of the product?
(A) Most horses like the medication.
(B) The medication is most effective between Days 4 and 5.
(C) Most horses will show improvement within 7 days.
(D) The effects of the medication are long lasting.
_____8. If a design flaw is discovered, what is the next logical step for the researcher?
A.
Make the design modification to solve the problem
B. Scrap the project and start again
C.
Obtain more money to support continued research
D. Create another prototype
WORKSHEET K—EXTRA CREDIT
1. Explain the mathematical relationship represented by the graph above.
2. A student wants to test the hypothesis that plants need soil to grow. What is the independent variable of the experiment?
Substance
Density (g/cm3)
Aluminum
2.7
Copper
8.9
Silver
10.5
Lead
11.3
3. You are given a sample of an unknown metal. You determine that the mass of the metal is 1050 g and its volume is 100 cm3. Based on the
information provided in the table above, what is the unknown metal?
4. How much is 2.3456% of 1.23456 grams of sodium chloride?
5. The ability of birds to change direction during flight depends on movements of their wingtips. Which technological advance did observation
of this phenomenon influence?