Round Rock High School
Advanced Chemistry
1st Nine Weeks
Unit 1: Matter
Unit 2: Atoms
Unit 3: Electrons
Name:
_______________________________________________________________
Teacher and Class Period:
________________________________________________________________
Table of Contents
Content Page Numbers
Unit 1 Warm-Ups Unit 1 Notes Unit 1 Test Review
Unit 2 Warm-Ups Unit 2 Notes Unit 2 Test Review
Unit 3 Warm-Ups Unit 3 Notes Unit 3 Test Review
Class Info by Teacher
Childs
Website: childschemistry.weebly.com Email: [email protected]
Remind Info: A Day - Text @ChildsADay to 81010 B Day - Text @ChildsBDay to 81010 Lestik
Website: magicalchemists.weebly.com Email: [email protected]
Remind Info: A Day - Text @LestikPAPa to 81010 B Day - Text @LestikPAPb to 81010 Rodgers
Website:
sites.google.com/roundrockisd.org/rodgerschem Email: [email protected]
Remind Info: A Day - Text @rodchema to 81010 B Day - Text @rodchemb to 81010
Quest Log-in
https://quest.cns.utexas.edu
Username: ____________________ (your UT EID, a combination of your initials and some numbers) Password: You will create your own when you first log in. Keep it secret. Keep it safe.
Chemistry Textbook Log-in
http://connected.mcgraw-hill.com
Username: rrisds###### (where the #s are your Student ID number) Password: s###### (where the #s are your Student ID number)
2 - 3 4 - 33 34 - 44 49 - 50 51 - 70 71 - 79 85 - 87 88 - 113 114 - 125
1st Marking Period: August-October 2021 SundayMondayTuesday Wednesday Thursday FridaySaturday 15 August 161718 A First day of school19 B 20 A21 2223 B 24 A 25 B26 A 27 B 28 2930 A 31 B 1 Sept. A2 B 3 A 4 5 6 Labor Day- No school7 B8 A 9B 10 A 11 1213 B 14 A 15 B 16 A 17 B 18 1920 A 21 B 22 A 23 B 24 A 25
SundayMondayTuesday Wednesday Thursday FridaySaturday 26 Sept. 27 Student Holiday/ Staff Development 28 B29 A 30 B 1 Oct. A2 3 4 B 5 A 6 B 7 A 8 B 9 1011 Student Holiday/ Staff Development 12 A 13 B 14 A 15 B End of 1st MP16 1718 A19 B20 A 21 B 22 A23 2425 B 26 A 27 B28 A 29 B 30 31
DO YOU NEED HELP? CHEMISTRY TUTORIALS Monday Tuesday Wednesday Thursday Friday 8:10 – 8:55 AMby appt only (talk to your teacher) 4:15 – 5:00 PMby appt only (talk to your teacher) DO YOU NEED TO TAKE A QUIZ? TEST? RETAKE? CHEMISTRY TESTING Monday Tuesday Wednesday Thursday Friday 8:00 – 8:55 AMby appt only (talk to your teacher) 4:15 – 5:00 PMby appt only (talk to your teacher)
Unit 1 Objectives: Physical and Chemical Properties of Matter
Accuracy, Precision, and Percent Error Content Objective:
I can collect data and make measurements with accuracy and precision.
Criteria for Success:
I can define and distinguish between accuracy and precision.
I can explain how accuracy and precision relate to the lab setting.
I can calculate the percent error of experimental measurements.
Significant Figures Content Objective:
I can express and manipulate chemical quantities using scientific conventions and mathematical procedures, including significant figures.
Criteria for Success:
I can determine the number of significant figures in a measurement.
I can perform mathematical calculations involving significant figures.
Scientific Notation Content Objective:
I can express and manipulate chemical quantities using scientific conventions and mathematical procedures, including
dimensional analysis, scientific notation, and significant figures.
Criteria for Success:
I can convert measurements between standard notation and scientific notation.
I can perform mathematical operations involving standard notation and scientific notation.
Metric Units Content Objective:
I can collect data and make measurements with accuracy and precision.
Criteria for Success:
I can explain the importance of a standard.
I can list the base units of measurement in the metric system for distance, volume, and mass.
I can explain how to use a system of prefixes to represent multiples of ten or submultiples of ten of these base units.
Unit Conversions Content Objective:
I can express and manipulate chemical quantities using scientific conventions and mathematical procedures,
including dimensional analysis, scientific notation, and significant figures.
Criteria for Success:
I can transform a statement of equality to a conversion factor.
I can utilize conversion factors to perform single-step and multi- step calculations.
States of Matter Content Objective:
I can compare solids, liquids, and gases in terms of compressibility, structure, shape, and volume.
Criteria for Success:
I can define compressibility, structure, shape, and volume.
I can determine if something is a solid, liquid, or gas based on a picture of its particles.
I can determine if something is a solid, liquid, or gas based on how it behaves when placed in different containers.
Classification of Matter Content Objective:
I can classify matter as pure substances or mixtures through investigation of their properties.
Criteria for Success:
I can identify a substance as an element, compound, homogeneous mixture or heterogeneous mixture.
I can explain the difference between elements and compounds.
I can explain the difference between heterogeneous and homogeneous mixtures.
Physical and Chemical Properties and Changes Content Objective:
I can differentiate between physical and chemical changes, physical and chemical properties, and intensive and extensive properties.
Criteria for Success:
I can identify a property or change as physical or chemical.
I can explain why a property or change is physical or a chemical.
I can define intensive and extensive properties.
I can identify a property as intensive or extensive.
Density
Content Objective:
I can differentiate between physical and chemical changes, physical and chemical properties, and intensive and extensive properties.
Criteria for Success:
I can define intensive property.
I can explain how intensive properties can be used to determine the identity of a substance.
I can recognize that density is an intensive property and be able to calculate density.
I can manipulate the density formula to solve for either mass or volume.
Unit 1 Daily Warm-Ups
Unit 1 Day 2
1. On average, the distance from the earth to the moon is 384,399,861 meters. A student calculates the distance to be 384,399,871 meters.
a. Rewrite both distances in scientific notation.
b. What was the error in the student’s measurement, in meters?
c. What was the percent error of the student’s measurement?
2. The standard sheet of paper has a length of 2.794 x 10–1 meters. A student measures a sheet of paper and finds the length to be 1.02794 x 101 meters.
a. Was the student’s measurement larger or smaller than the true length of the paper?
b. Rewrite both lengths in standard notation.
c. What was the error in the student’s measurement, in meters?
d. What was the percent error of the student’s measurement?
3. Why was the percent error different between the moon measurement and the paper measurement, even though the error in meters was the same?
Unit 1 Day 3
1. Goal: What is one skill you’re going to focus on improving during this unit to improve your success in Pre-AP Chemistry? What will you do to improve this skill?
2. How many sig figs are in 0.2030000100? ________ 3. How many sig figs are in 1,050,200? _________
4. Calculate. Give answer with correct number of sig figs. (29.634 + 0.93) ÷ (100. – 5.63) = ___________
Unit 1 Day 4
1. Express the following in scientific notation a. 129,360 L
b. 0.00239 g
2. There are 2.54 cm in 1 inch. How many centimeters are in 2.6 feet?
3. How many mm are in 2.37 Mm?
Unit 1 Day 5
1. Convert 37 μL to nL. Show your work in dimensional analysis. Report your answer in scientific notation.
2. Which state(s) of matter have a definite volume? _______________
3. Which state(s) of matter have an indefinite shape? _______________
4. Identify the following as element (E), compound (C), heterogeneous mix (He), or homogeneous mix (Ho).
a. salt water ____ c. air ____ e. sulfuric acid (H2SO4) ____
b. oxygen gas (O2) ____ d. granite ____
Unit 1 Day 6
1. Convert 2.932 nm to mm. 2. How many ng are in 2.6 kg?
3. Identify each property as Physical/Chemical AND Intensive/Extensive (Circle one).
Color ( P / C , I / E ) Density ( P / C , I / E ) Reactivity ( P / C , I / E ) Unit 1 Day 7
1. Reflection: What topics in this unit do you feel most confident on? What topics do you still find challenging or confusing? What are you going to do between now and test day to help increase your success with the challenging content?
Unit 1 Test Next Class!!!
Unit 1 Part 1: Accuracy, Precision, and Percent Error
Accuracy and Precision
● Accuracy – how closely a measurement (or the average of a set of measurements) agrees with its ____________________ value (< 5 % error!)
● Precision – how close several trials making the _____________ measurements are to each other (________________________________________)
Accurate? ______ Accurate? ______ Accurate? ______ Accurate? ______
Precise?________ Precise?________ Precise?________ Precise?________
Example: Wayne and Bruce measured the length of a pencil three times and got the following data. The manufacturer says that the length of the pencil is 19.0 cm.
Measurement 1 Measurement 2 Measurement 3
Wayne 19.0 cm 18.9 cm 19.1 cm
Bruce 18.2 cm 18.2 cm 18.2 cm
1. Who had the most accurate measurements and why?
2. Who had the most precise measurements and why?
100.000 98.89 94.90
Percent Error:
(accepted value-experimental value)
accepted value ×100=Percent Error
• Accepted value: _____________ value (truth)
• Experimental value: ________ (measurements)
• Percent error has a ___________________ value if accepted value is greater than experimental value.
• Percent error has a ___________________ value if accepted value is less than experimental value.
Practice Makes Perfect!
Two technicians independently measure the density of a substance. Technician A records values of 2.000, 1.999, and 2.001 g/mL. Technician B records values of 2.5, 2.9, and 2.7 g/mL. According to a reference table, the accepted
density for the substance is 2.71 g/mL.
a. Calculate each technician’s average measurement.
b. Which technician’s measurements are more precise? Explain.
c. Which technician’s measurements are more accurate? Explain.
d. What is Technician B’s percent error?
Examples:
1. Calculate the percent error in an experimental mass measurement of 5 g if the accepted value is 10 g.
2. A teacher calculates the molar mass of sodium hydroxide as 37 g/mol. The true molar mass of sodium is 40 g/mol.
Which is the teacher’s percent error?
A. 37 g/mol
40 g/mol×100 C. 3 g/mol
40 g/mol×100 B. -3 g/mol
37 g/mol×100 D. 40 g/mol
37 g/mol×100
3. There are 34 questions on a test. Alfred answers 22 of them correctly. What is Alfred’s percent error?
Unit 1 Part 2: Scientific Notation
Scientific Notation
Used to make very ____________ or very _____________ numbers easier to handle using powers of ______.
How to Convert Quantities to Scientific Notation Example
1. Move the decimal point in the quantity expressed in long form right or left until there is only one ___________________ digit to the left of it.
310,000
2. Use the number that results as the coefficient, M.
3. Count the number of decimal places moved, and call that number n, and use it as the exponent of 10.
4. Your final quantity should be expressed in the form ______________ (scientific notation).
5. NOTE: Make the exponent ____________ if the decimal moved
to the right. 0.0010
Large negative exponents come from very small values.
You should start and end with the same number of sig figs.
Examples:
1. Change the following between scientific notation and standard notation.
a. 8,800,000,000 m b. 0.00015 kg
c. 1.9 x 10−4 m d. 2.01 x 103kg 2. Determine which value is larger.
a. 6.93 x 102 or 6.93 x 10-8 b. 2.4293 x 10-36 or 2.4293 x 10-12
c. 7.12 x 103 or 1.363 x 1012 d. 5.19 x 103 or 2.01 x 103
Practice Makes Perfect!
1. Write each of the following in scientific notation.
a. 325 b. 0.36 c. 70
d. 0.00573 e. 5921 f. 0.0005438 2. Write each of the following in standard notation.
a. 3.64 x 104 b. 2.97 x 10−4 c. 3.9734 x 105
d. 5.65 x 10−1 e. 6.7978 x 100 f. 3.7283 x 10−4 3. Determine which of the following values are larger
a. 5.25 x 10−6 or 2.77 x 10−3 b. 1.00001 x 1012 or 9.9999 x 102 c. 1.00001 x 10−2 or 9.9999 x 10−12
d. 1.2345 x 10−16 or 9.9876 x 104 e. 2.475 x 1099 or 2.474 x 1099 f. 4.385 x 10−1 or 9.9999 x 101 Scientific Notation on the Calculator
There are many ways to enter quantities in scientific notation into your calculator. We will use a method that replaces the x10^ with ______. This is the ________________ and most _________________ way to use scientific notation on your calculator.
Note: You will need to enter answers online using this method as well.
6.02 x 1023 will appear as 6.02E23 1.709 x 10−4 will appear as 1.709E−4
Practice Makes Perfect!
1. Carry out the following operations. Express the results in scientific notation with correct units. Round answers to three digits.
a. 4.0 x 10−3 + 6.85 x 10−3 – 1.05 x 10−3
b. 2.290 x 107 ÷ 4.33 x 103
c. 1.54 x 10−1 ÷ 2.36 x 10−4
Examples: Carry out the following operations. Express the results in scientific notation with correct units. Round answers to three digits.
1. 7.20×103 x 8.08x103
2. 4.74 x 103 + 7.71 x 103 + 1.05 x 103
Unit 1 Part 3: Sig Figs Crash Course!
Significant Figures (otherwise and forever known as _____________) in a measurement consist of all the digits known with certainty plus one final digit, which is estimated.
____ ____ ____ . ____ ____ ____ ____ ____ ____ . ____ ____ ____
A quick review: what are the different place values called?
3, 1 2 0 . 7 4 5
Always measure to the place value indicated by the markings on your instrument PLUS ONE MORE.
Practice Makes Perfect!
Markings:
______________________
Measurement:
______________________
Markings: __________________________
Measurement: _____________________
Examples: Using correct significant figures, what is the measurement that is represented in each picture?
(Remember to measure from the bottom of the meniscus (the curvy part)!) Markings:
______________________
Measurement:
______________________ Markings: __________________________
Measurement: ________________________
Let’s Discover How Sig Figs work!
Number # of Sig Figs Number # of Sig Figs
27.9 3 2,030. 4
0.23 2 2,030 3
408 3 480 2
0408 3 29.0 3
0.002134 4 0.2080 4
6.022 x 1023 4 4.00 x 10−3 3
6.0 x 1023 2 5 x 10−7 1
Rules for Determining Significant Figures 1. Non-zeros:
2. Sandwich zeros (zeros in the middle of non-zeros ):
3. Leading zeros (zeros to the left of non-zeros):
4. Trailing zeros (zeros to the right of non-zeros):
5. Scientific notation:
6. Counting Numbers (one kitten, two kittens, etc) and Conversion factors (for example, 12 inches per 1 foot) are considered exact values and have an _________________ number of sig figs.
Let’s Test Your Rules! Complete the charts below by counting the number of significant figures in each measurement.
Measurement # of sig figs? Measurement # of sig figs? Measurement # of sig figs?
100 g 0.1 mL 1 x 103 m
100. g 0.001 mL 1.0010 x 108 m
10.010 g 0.0050020 mL 9.80 x 1024 m
Practice Makes Perfect!
Number How many Sig Figs? Number How many Sig Figs?
3.0800 mL 55 puppies
0.00418 g 1,800. m
0.00000040 L 1,800 m
1.005 kg 91,600,000 g
3 people 2.998 x 108 m/sec
Using Significant Figures in Calculations
Multiplication / Division: the answer can have no more significant figures than are in the measurement with the FEWEST ___________ number of significant figures.
Addition / Subtraction: the answer must have the same ___________ value for the estimated digit as the measurement having the least precise (i.e. least ______________) place value. (the one furthest to the left)
Let’s Practice!
1. Which of the following numbers is measured to the least precise place value?
a. 2.03 or 2.0 c. 1.0 x 10−3 or 1.0 x 10−4 b. 0.003 or 0.100 d. 4 x 1023 or 7 x 1024
2. 2 + 3.00 + 15.000 = __________________ 3. 12,000 + 560 + 500 = __________________
Do NOT round any of the numbers you are given until the very end of the problem (Plug numbers into your equations in their full, precise glory)
Hey, Listen: PEMDAS. It’s still a thing.
Examples:
1) 1.052 x 12.504 x 0.53 =
2) 12.500 ÷ 2.000 =
Examples:
1) Which of the following numbers is measured to the least precise place value?
a. 1,200 or 1,230 b. 1.00 or 0.153 or 121
2) 2.345 0.07 + 2.9975
3) 5.9
− 0.241 4) 1,010
2.9 + 0.76
One more example for fun and glory: Combining mathematical operations!
6.78 x 5.903 x (5.489 − 5.01) =
Practice Makes Perfect!
Rules for Significant Figures (provided on your formula chart!!!) 1. Non-zero digits and zeros between non-zero digits are always significant.
2. Leading zeros are not significant.
3. Zeros to the right of all non-zero digits are only significant if a decimal point is shown.
4. For values written in scientific notation, the digits in the coefficients are significant.
Rules for Sig Fig Calculations (NOT provided - must be memorized!) Hint: Alpha order!
1. Adding/subtracting: round to least precise place value 2. Multiplying/dividing: round to least precise total number
More Tasty Calculations Practice!
Calculator Answer Rounded Answer (with Correct # of Sig Figs) 1. 170 + 3.5 – 28
2. 47.0 ÷ 2.2
3. 691,300 ÷ 5.022 – 4.31
4. (0.054 + 1.33) × 5.4
Oh yes, even more practice!
Directions: Measure the following to the correct number of significant figures.
Directions: Determine the number of significant figures.
1.0.02 ________ 2. 142 ________ 3. 0.02020 ________ 4.0.073 ________
5. 501 ________ 6. 1.071 ________ 7. 501.0 ________ 8. 10810 ________
9. 5000 ________ 10. 5.00 ________ 11. 5000. ________ 12. 1.20 x 103________
Directions: Round your answer to the correct number of sig figs.
Calculator Answer Rounded Answer (with Correct # of Sig Figs) 1. 140 × 35
2. 0.003 + 0.0048 + 0.100
3. 67.35 ÷ (1.401 – 0.399)
4. (6.23 + 3.111 – 0.05) × 14.99
5. 3.14159 × (4.17 + 2.150)
1. ___________
2. ___________
3. ___________
4. ___________
Unit 1 Part 4: The Metric System and Conversions
Conversions: A statement of _______________ which describes the relationship between two equivalent quantities expressed in different units.
Conversion factor: a ________________ derived from a statement of equality used to convert from one unit to the other.
• Conversion factors are equal to ______. Therefore, when you convert you are not changing the amount of what you have, just the _________ you are using to represent the amount.
• When completing conversion calculations, choose the conversion factor that will ____________
undesired units and leave desired units.
Statement of Equality Possible Conversion Factors There are 12 eggs in 1 dozen. 12 eggs 1 dozen
1 dozen 12 eggs
A Metric Ton of Fun!
Base Units: The metric system simplifies measurement by using a single base unit for each quantity.
Table 1: Base Units
Quantity Symbol Base Unit Symbol
distance d meter m
volume V liter L
mass m gram g
Prefixes: Base units can be adjusted to a more appropriate magnitude by including a prefix.
Table 2: SI Prefixes and Symbols
Prefix Symbol Conversion Factors
giga- G 1 Gm = 109m
mega- M 1 Mm = 106m
kilo- k 1 km = 103m
hecto- h 1 hm = 102m
deca- da 1 dam = 101m
BASE
UNIT m, L, or g m, L, or g
deci- d 1 dm = 10−1m 101 dm = 1m centi- c 1 cm = 10−2m 102 cm = 1m milli- m 1 mm = 10−3m 103 mm = 1m micro- µ 1 µm = 10−6m 106 µm = 1m nano- n 1 nm = 10−9m 109 nm = 1m
The Great and Mighty King Henry Died Basically Drinking Chocolate Milk Monday Night
Practice Makes Perfect!
Units Statement of Equality 2 Possible Conversion Factors
1. minutes, hours There are _____ minutes in _____ hour.
2. inches, feet There are _____ inches in _____ foot.
3. liters, gigaliters There are _____ liters in _____ gigaliter.
4. narfs, kilonarfs
(I made narfs up, but they’ll work the same as any other unit!!)
But How Do We Use Them?
______________________________________ is a structured method to convert numbers.
How many hours are in 4.0 days?
= __________
A trick to converting units is to convert to the base unit and then convert to the desired unit mLL µL
×
Practice Makes Perfect!
Tasty Conversion Practice: Show all work using dimensional analysis!
1. A student measures 5.20 x 105 cm of magnesium ribbon. Determine the length of ribbon in meters.
2. Three weeks ago, Andres’s weight was two hundred eighty-five and two tenths kilograms. He has since lost nineteen thousand, five hundred thirty grams. What is his current weight in kilograms?
3. Susanna is 5.33 ft tall. What is her height in centimeters? (1 inch = 2.54 cm) Examples:
1. A student has 4.35 x 1016 kilobytes (kB) of data stored on her computer. How many megabytes is this?
2. A student had a length of string that was 1.25 decameters long. After cutting off 220.4 cm of string, how much string was left? (Answer in units of centimeters).
3. Use the following conversion factors to answer the question below.
24 tillers = 7 sillybuckets 21 yellow rilly boopers = 2 sted buuts
8 sted buuts = 3 sillybuckets How many yellow rilly boopers are equal to 18 tillers?
4. Use the following conversion factors to answer the question below.
1 Longhorn = 23 Sooners 4 Sooners = 9 Aggies 3 Red Raiders = 14 Aggies How many Red Raiders are the equivalents of 3 Longhorns?
5. If we are in class for 1.5 hours,
a. how many nanoseconds are we in class?
b. how many years?
2. Convert 3.644 centimeters to nanometers.
3. Convert 74.5 kL to µL.
4. Convert 2.4 kg to pounds. (1 lb = 453.592 g)
5. Michael was collecting chicken eggs on his farm. If he collected 29 eggs, how many dozen eggs does Michael have?
Unit 1 Part 5: Density
Intensive & Extensive Properties
Extensive property: a characteristic that depends on the ______________ of matter present (how much you have).
Examples: mass, length
Intensive property: a characteristic that does _______ depend on the amount of matter present.
Examples: color, melting point (temperature at which something melts) Density
The ratio of _____________ to ______________
Units for Density
• Fluids (i.e. ___________ or _____________):
• Solids:
Hey, Listen! ____ mL = ____ cm3
Density is an _______________ property of a substance and can be used to help _______________ a substance.
An object will ___________________ if its density is less than the density of the fluid it is placed in.
Density of water = ___________: ___ mL of water has exactly ___ g of mass!
Water Displacement Method
Method used to measure the ___________ of an irregular object
1. Record _____________________ of water in a graduated cylinder 2. Place the object in the graduated cylinder
3. Record the ____________________of water
4. Always read volume at the ______________________________________!
REMEMBER! When measuring in lab, estimate _________________ beyond what the ruler or graduated cylinder is marked (to get correct __________________)
Everything you know PLUS ONE MORE
Examples:
1. A container is filled to the brim with 500. grams of honey, which has a density of 1.42 g/mL. Calculate the volume of container.
Density= Mass
Volume
Practice Makes Perfect!
1. A piece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0 grams.
a. What is the density of the wood? (Remember geometry? Volume = L x W x H)
b. Will this piece of wood float in water? Explain.
2. What is the mass of 0.125 L of ethanol? Density of ethanol = 0.789 g/mL.
Examples:
2. Consider a block of marble that displaces 287 cm3 of water and has a mass of 869 g.
a. What is its density?
b. Will it float in:
i. H2O (l)? Why or why not?
ii. Hg (l)? Why or why not? (Hint: the density of liquid mercury is 13.6 g/mL).
3. An empty container has a mass of 1.3 grams. When it has been filled with 17.9 mL of a mysterious liquid, it has a mass of 19.3 grams.
a. What is the density of the mysterious liquid?
b. What do you think is the identity of the mysterious liquid? ______________________
3. When a piece of metal with a mass of 99.43 g is dropped into a graduated cylinder containing 23.55 mL of water, the water level rises to 28.84 mL. What is the density of the metal?
4. A cup of metal beads was measured to have a mass of 425 grams. By water displacement, the volume of the beads was calculated to be 48.0 cm3. Given the following densities, identify the metal. Justify your answer with calculations.
A. Gold: 19.3 g/mL C. Bronze: 9.87 g/mL
B. Copper: 8.66 g/mL D. Lead: 11.4 g/mL
Unit 8 Part 6: Density of Starburst Mini-Lab
Materials: Starbursts, balance, ruler Procedure:
1. Take the mass of one starburst.
2. Using the ruler, measure the length, width, and height of one starburst.
3. Take the mass of two starbursts.
4. Stack the two starbursts and measure the length, width, and height of the stack 5. Repeat with three starbursts and four starburst
6. Record all data in the data table.
7. Calculate the volume and density for each set of starbursts
Data:
Number of
Starbursts Mass (g) Length (cm) Width (cm) Height (cm) Volume (cm3) Density (g/cm3)
Analysis Questions:
1. Is density an intensive or extensive property? Justify your response.
2. Could density be used to identify a substance? Explain.
3. Ask your teacher for the accepted value for the density of starburst: _____________
a. Use this value to calculate your percent error.
b. Was your experimentally derived value of density accurate? Why or why not?
Unit 1 Part 7: Density Lab (Unit 1 Formal Lab)
The Crime: It was a typical weekday night at Round Rock High School and an innocent chemistry teacher was furiously entering grades in her grade book. She was just entering the last grades when she heard the door open.
Before she could turn around to see who had entered, she was knocked unconscious! She awoke several hours later with a terrible headache and discovered to her shock and dismay that she had been shot with BBs by an unknown assailant.
She was given several samples of BBs that were removed from her body in the emergency room and the police collected several samples of BBs from the classroom. During the investigation, several names were provided to Mr.
Groff as potential suspects in this heinous crime. Mr. Groff reported these names to the Round Rock police. Round Rock police then searched the homes of these suspects and discovered BBs of different materials in each of their homes.
Densities of Known Materials
Suspect Material Density Characteristics
Dyed Polypropylene 0.87 g/mL Green
Dyed PVC 1.40 g/mL Green
Dyed Polystyrene 1.02 g/mL Green
Dyed Acrylic 1.17 g/mL Green
Experimental Method: You will use the experimental method of volume by displacement to calculate the density of the BB sample from the crime scene, and use this information to match the BBs found at the crime scene to the BBs of one suspect, thereby catching this malicious criminal. Good luck!
Data Table 1: Physical Properties of BBs Physical Properties (Be specific!)
Evidence sample
Density pre-lab: Observe your sample of BBs, and write down some physical properties of the BBs in the space above.
Density Lab Procedure:
1. Fill a 100 mL graduated cylinder with approximately 70.0 mL of water. Record the exact volume in your data table.
2. Determine the mass of your 100 mL graduated cylinder that is filled with the 70.0 mL of water. Record the exact mass.
3. Add enough BBs so that the volume of your graduated cylinder increases by approximately 5.0 mL.
Determine the new volume to the tenths place and record this exact volume.
4. Place the graduated cylinder with the water and first addition of BBs on the electronic balance. Record the exact mass.
5. Again, add enough BBs so that the volume of your graduated cylinder increases again by a volume of approximately 5.0 mL (It should be filled up to about 80.0 mL at this point). Record this exact volume.
6. Place the graduated cylinder with the water and second addition of BBs on the balance. Record the exact mass.
7. Again, add enough BBs so that the volume of your graduated cylinder increases again by a volume of
approximately 5.0 mL (It should be filled up to about 85.0 mL at this point). Record this exact volume in your data table.
8. Place the graduated cylinder with the water and third addition of BBs on the electronic balance. Record the exact mass in your data table.
9. Cleanup and Disposal: Clean all apparatus and your lab station. Return equipment to its proper place.
Data Table 2: Mass and Volume Data
No BBs First Addition Second Addition Third Addition mass
(g) volume
(mL)
Calculations: ( Don’t forget about sig figs! 😊😊)
1. Determine the mass of just the BBs after the first, second, and third additions. REMEMBER: You want the mass of just the BBs, so you will need to subtract the mass of the graduated cylinder and water from the mass of the graduated cylinder, water, and BBs. Record these masses in your calculations table.
2. Determine the volume of just the BBs after the first, second, and third additions. REMEMBER: You want the volume of just the BBs, so you will need to subtract the final volume of water from the initial volume of water. Record these volumes in your calculations table.
3. Calculate the density of the BB sample after each addition, and the average density of the sample.
4. After identifying the culprit (see #1 of the analysis section), calculate the percent error of your average density. Use the density of your culprit’s BBs as your accepted value. (Please ignore sig figs with your percent error calculation and round your final answer to 3 sig figs). Show your work below!
% Error= �accepted-experimental
accepted � (100)
Calculations Table: Mass, Volume, and Density
First Addition Second Addition Third Addition Average % Error mass
(g) n/a n/a
volume
(mL) n/a n/a
Density (g/mL)
Analysis:
1. Who attacked the innocent chemistry teacher, and how do you know?
2. The defense attorney for the suspects in this class argues that it is impossible for you to prove her clients’
guilt. She says that a graduated cylinder full of BBs will not have the same density of a single BB. The attorney continues that density is an extensive property and not an intensive property and that your experimental data should be thrown out. Do you agree? Use your data to justify your response.
Error Analysis: (Do NOT include questions in your lab report! Only include your answers, in complete sentences.) 1. For each of the possible lab errors described below, what effect would this error have on your data and on
your final calculated density? (Yes, you need to answer these questions even if you didn’t have this error.) Error #1: If some of the BBs didn’t sink completely - they floated and thus were not completely submerged in the water,
a. What was the effect of this lab error on your data? Be specific: did this affect your measured mass or measured volume? Was that value higher or lower than the actual value?
b. What affect did this lab error have on your calculations of mass or volume? Be specific: was the calculated mass or volume higher or lower than it was supposed to be?
c. Ultimately, would this lab error cause your calculated BB density to be higher or lower than the actual density value, and why?
Error #2: If some air bubbles became trapped among the BBs when they were added to the water, d. What was the effect of this lab error on your data? Be specific: did this affect your measured mass or
measured volume? Was that value higher or lower than the actual value?
e. What affect did this lab error have on your calculations of mass or volume? Be specific: was the calculated mass or volume higher or lower than it was supposed to be?
f. Ultimately, would this lab error cause your calculated BB density to be higher or lower than the actual density value, and why?
2. Considering the two errors above and your data and calculated percent error, which of the errors described above do you think would most likely explain YOUR percent error? Be sure to consider if your calculated density was higher or lower than your actual density.
Unit 1 Part 8: States of Matter
Solid Liquid Gas
___________ volume and shape (volume and shape don’t
depend on container)
Definite volume and takes shape of the part of the container it
occupies
Assumes shape and volume of its container
Relatively _______ Kinetic Energy (only movement is
vibration)
Medium amount of kinetic energy (particles can vibrate and slide)
Relatively ________ Kinetic Energy (particles can move
any way possible) Relatively ___________ amount
of order (particles are _____________)
Medium Amount of Order (particles have some
organization)
Relatively _____ order (particles have almost no
organization) Very __________ Rate of
Diffusion (particles mix ________) (think of pouring
sand into a bucket of salt)
Medium Rate of Diffusion (particles mix readily) (think milk
into coffee)
Relatively high rate of diffusion (particles mix very
quickly - think Axe Body Spray)
Relatively _____ Density (high mass in little volume)
Medium Density (medium mass for the volume it has)
Relatively ____ Density (small mass for large volume) __________________
(can’t be squished)
Relatively incompressible (can squish a little, but enough pressure will turn liquid into solid)
High Level of Compressibility (easily squished)
__________ attractive forces between particles
Medium attractive forces between particles
Weak attractive forces between particles
Compressibility
______ ______ ______
Classifying Matter
• Matter: anything that occupies space and has mass.
• We classify matter according to its composition (the basic components that make it up).
• Pure Substances - Must be separated chemically (bonds broken) o Same/fixed ____________________________
o Elements
Cannot be broken down and still maintain identity
One type of atom (basic building blocks)
Found on the __________________________________
o Compounds
Chemical combination of ___________ or more elements in fixed, definite proportions
Cannot be separated by physical means
Properties of compound are _____________________ than individual elements
• Mixtures - Can be separated by physical means
o Formed when two or more substances (s, l, g, aq) are physically combined o All substances in mixture retain their own __________________ properties o Heterogenous
Parts of the mixture are __________ evenly distributed (poorly mixed)
Does ____________ look the same throughout o Homogenous
Parts of the mixtures are __________________ distributed (evenly mixed)
Also called a ___________________
Matter
Can it be physically separated?
NO!
Can it be chemically separated into simpler substances?
Pure Substances
Uniform throughout?
Mixtures
YES!
NO! YES! NO! YES!
Element
Examples 1.
2.
3.
Compound
Examples 1.
2.
3.
Heterogenous Mixture
Examples 1.
2.
3.
Homogenous Mixture (Solution)
Examples 1.
2.
3.
Methods for Separating a Mixture: Both heterogeneous and homogeneous mixtures can be separated by ________________ means into the component parts that make up the mixture.
1. A solid and liquid mixture can be separated by pouring the mixture through a ____________ paper designed to allow only the liquid to pass.
2. A homogeneous mixture of liquids can be separated using _________________________, a process in which the mixture is heated and the more volatile (more easily vaporized) liquid is boiled off first. A condenser is then used to recollect the vaporized component.
3. Paper ______________________________ takes advantage of the fact that different components of a homogeneous mixture have different attractions to a solvent and paper.
Practice Makes Perfect!
Part I: Identify each of the following images as an element, compound, or mixture!
Type of matter?
____________________________________
How do you know?
Type of matter?
____________________________________
How do you know?
Type of matter?
____________________________________
How do you know?
Type of matter?
____________________________________
How do you know?
Part II: Identify the following as element (E), compound (C), heterogeneous mix (He) or homogeneous mix (Ho).
a. Table salt _________ b. Nitric acid (HNO3) _________ c. Sugar (Glucose) _________
d. Carbon Dioxide (CO2) _________ e. Milk _________ f. Air _________
g. Nitrogen gas (N2) _________ h. Zinc (Zn) _________ i. Pulpy orange juice _________
Part III: Use the particle representations below to answer #1-5. Answer choices may be used more than once or not at all!
A B C D E
1. Compound ______ 2. Nitrogen, N2 ______ 3. Mixture of two elements ______
4. Element ______ 5. Mixture of water, H2O, and hydrogen H2 ______
