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Chemistry Unit 3A Packet 2 Essential Questions

1) How do scientists express quantities and convert them into different units? 2) How can properties like density be used to identify substances?

Chemistry Unit 3A Packet 2 Learning Goals

LEARNING GOAL DATE INTRODUCED

RATE HOW WELL YOU UNDERSTAND

LEARNING GOAL

LG 3.5: Explain the difference between accuracy and precision. 9/25 5 4 3 2 1

LG 3.6: Convert measurements into scientific notation 9/29 5 4 3 2 1

LG 3.7: Perform mathematical operations involving significant figures 9/29 5 4 3 2 1

LG 3.8: Transform a statement of equality into a conversion factor 9/30 or 10/1 5 4 3 2 1

LG 3.9: Convert between metric prefixes 9/30 or 10/1 5 4 3 2 1

LG 3.10: Convert between metric and English systems 9/30 or 10/1 5 4 3 2 1

LG 3.11: Convert between temperature scales 9/30 or 10/1 5 4 3 2 1

LG 3.12: Distinguish between fundamental and derived units and convert derived units 10/5 5 4 3 2 1

LG 3.13: Perform density calculations 10/5 5 4 3 2 1

LG 3.14: Perform percent error calculations 10/6 or 10/7 5 4 3 2 1

LG 3.15: Identify a substance by measuring its density 10/6 or 10/7 5 4 3 2 1

Chapters In E-Textbook

Scientific Notation – pages 175-179 Significant Figures in Multiplication and Division– pages 153-156

Significant Figures in Addition and Subtraction– pages 157-160 Metric Unit Conversions – pages 71-76

Derived Units – pages 131-136 Factor Labeling (Unit Conversion) – 180-183

Density – pages 137-142

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Chemistry Unit 3A Packet 2 Assignment List

ASSIGNMENT NAME PAGE # DATE DUE

CHEMIISTRY UNIT 3A PACKET 2 LEARNING GOAL LIST 1 N/A

CHEMISTRY UNIT 3A PACKET 2 ASSIGNMENT LIST 2 N/A

WARMUPS 3

EQUATIONS AND CONSTANTS RESOURCE PAGE 4 N/A

NOTES: SCIENTIFIC NOTATION AND SIG FIG CALCULATIONS 5 N/A

SCIENTIFIC NOTATION ACTIVITY 6

SIG FIG CALCULATIONS WS 7

QUIA: SIGNIFICANT FIGURES CALCULATIONS PART I QUIA

QUIA: SIGNIFICANT FIGURES CALCULATIONS PART II QUIA

UNIT CONVERSION NOTES 8 N/A

UNIT CONVERSION ACTIVITY 9-10

UNIT CONVERSION PRACTICE 11

MYSTERY LIQUID DENSITY LAB 12

DERIVED UNITS / DENSITY NOTES 13 N/A

MORE UNIT CONVERSION PRACTICE 14

DENSITY LAB 15-18

BEVERAGE DENISTY LAB 19-20

QUIA: UNIT 3A REVIEW QUIA N/A

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CHEMISTRY WARM-UPS: Be sure to complete NAME __________________ PERIOD ___ ALL information! NO BLANKS! DATE____________ Learning Goal _____________________________________________ Write the WARM-UP Question: Your Answer: Correct Answer/Reflection: Rate:____ DATE____________ Learning Goal _____________________________________________ Write the WARM-UP Question: Your Answer: Correct Answer/Reflection: Rate:____ DATE____________ Learning Goal _____________________________________________ Write the WARM-UP Question: Your Answer: Correct Answer/Reflection: Rate:____

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Scientific Notation + Significant Figure Calculations Scientific Notation: A method of expressing any number as a number between 1 and 10 (known as the coefficient) multiplied by 10 raised to a power (known as the exponent). Addition and Subtraction Rule For Significant Figures: When measurements are added or subtracted, the number of significant digits to the right of the decimal in the answer is determined by the measurement with the fewest digits to the right of the decimal. Multiplication and Division Rule For Significant Figures: When measurements are multiplied or divided, the answer will have no more than the measurement with the fewest number of significant figures. Rounding: If the digit is smaller than 5, drop the digit and leave the remaining unchanged. If the digit is 5 or larger, drop the digit and add 1 to the preceding digit. Scientific Notation Example Problems: 1) 0.00458 mm 2) 8.348 x 106 km 3) 438,904 s 4) 3.02 x 10-4 L

Adding/Subtracting Example Problems: 1) (6.23 kL) + (5.34 kL) 2) (4.87 mm) - (0.3 mm) 3) (7.21 mg) + (43.8 mg) 4) (3.57 mL) – (1.432 mL) Multiplying/Dividing Example Problems: 1) (4.8 km) x (2.0 km) 2) (3.333 m) / (1.5 m) 3) (8.8 L x 2.00 L) 4) (4 mm) / (3.0 mm)

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Scientific Notation Activity Name ____________________________ Period _________ Directions: You are given 6 cards with various measurements listed on them. You will be asked to sort the cards in several ways. NOTE: Do not write on the index cards! Part 1: It is hard to compare numbers in standard notation and numbers in scientific notation. Below, place the 6 measurements in two columns and convert each number to standard notation or vice versa. Standard Notation Scientific Notation 1. 2. 3. 4. 5. 6. Part 2: You will be directed to sort the cards in several different ways. Write down the correct answer after checking with the teacher. Category 1:

Category 2: Category 3:

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Unit Conversion Notes and Example Problems Unit Conversion: A problem-solving method that uses the fact that any number or expression can be multiplied by one without changing its value. Also called factor labeling and dimensional analysis. Conversion Factor: A mathematical fraction used to convert a quantity of one unit to a quantity of different units. A statement of equality ( ____ = _____) can be turned into a ratio (fraction). Ex: 1 L = 1000 mL 1 L or 1000 mL 1000 mL 1 L How to do a Conversion Problem:

1) Write down on the left where you are starting (your initial measurement). 2) Write down on the right side what units you are trying to get to. 3) Create conversion factors that will get you from #1 to #2. Units in the numerator will be cancelled by

identical units in the denominator. 4) Answer will have same number of Significant Figures as the initial measurement.

Example Problem: How many seconds are there in 2.0 days? Unit Conversion Practice Problems: 1) Metric to Metric Conversion (Conversions on page 4) How many meters in 108 nm? 2) Metric to English Conversions (Conversions on page 4) How many feet in 40 km? 3) Temperature Conversions (Equations on page 4) Convert 42˚C to F?

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/10 Unit Conversion Activity Name ____________________________ Period _________ Directions: You have travelled to a strange new planet (Planet X). You are slowly trying to figure out relevant units for various life functions. Using the cards given to you, set up the correct unit conversion, write down your work, and calculate the final answer (be sure to include units!). 1) (Green cards) The first thing you want to know is how much do you weigh on this new planet? 1 pound is about 5 thumps. How many thumps would a 110 pound person weigh? 2) (Pink cards) The second thing you attempt to figure out is how much money you have. 2 quiks are exchangeable for 1 blip. 3 blips are equal to 2 U.S. dollars. How many quiks can you get if you brought 250 U.S. dollars? 3) (Blue Cards) Time also seems different. One alien remarks that it will take you 10 borks to get to your hotel. You pick up in general conversation that 1 bork is 3 wades and 4 hours is equal to 9 wades. How many minutes will it take you to get to the hotel? 4) (Blank White Cards) Finally, you attempt to figure out the aliens’ measuring system for length. You ask a stranger how far away the nearest town is and the alien remarks it is about 84 molinas. (3 molina = 1 yadi) You estimate that a yadi is 2 km long. How many miles away is the nearest town (Hint: 1.6 km is about 1 mile)? **You will have to make your own cards for this problem.**

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Group Activity When the teacher calls your group to the demo table, each member of your group will each receive two index cards with unit conversion ratios. Each group member can only touch his/her own two cards. Set up the unit conversion factor cards to answer the following problem: How many “I’s” are in one “A?”

x x x x

x x x =

1A x

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Unit Conversion Practice Problems

Metric/Metric Conversions

1. 50.0 km to meters 2. 47.9 mL to liters 3. 155kg to grams

4. 40 m to kilometers 5. 1 m to nanometers English/Metric Conversions

1. 34.4 inches to cm 2. 557 meters to feet 3. 78.0 L to gallons

4. 5678 grams to pounds 5. 882mL to quarts Temperature Conversions

1. 2.45 C to F 2. -40.0 C to F 3. -345 F to C

4. 355 K to C 5. 25.0 C to K

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Derived Units/Density Notes Derived Units: Units which can be expressed by other units using the mathematical operations of multiplication or division. Ex: m3, m/s. Example Problems: Convert 43.4 cm2 to inch2. Convert 60 miles/hr to km/sec. Density: The amount of mass per unit volume. Density is an example of a derived unit. Density = mass / Volume Example Problems: Copper has a density of 8.60 g/mL. How many grams would 40.0 mL of copper contain? What is the density of a substance that has a mass of 420 g and a volume of 300 mL?

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More Unit Conversion Practice Problems

Derived Unit Conversions

1) 89.9 km2 to miles2 2) 90.2 L to cm3 3) 55.0 mph to km/s 4) 12.4 m/s to inches/min Density Problems 1) Find the density of concrete if a rectangular piece of 2.00cm x 2.00 cm x 9.00 cm has a mass of 108g. 2) Bismuth has a density of 7.87 g/mL. What is the mass of 3.74 mL of Bismuth? 3) Iron has a density of 7.87 g/mL. What volume would 26.3 g of Iron occupy? 4) Cerium sulfate has a density of 3.17 g/mL. Calculate the volume of 599 g of this substance.

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Beverage Density Lab Purpose: Identify sugar content in a beverage by using density. Introduction: Procedure: Important: Use the same graduated cylinder throughout and the same scale.

1. Place the graduated cylinder on the scale and zero the scale. 2. Pour 20.0 mL of sugar solution into the graduated cylinder (be as precise as you can). 3. Mass the liquid. Record this mass in the table. 4. Repeat steps 1 and 2 four more times, for a total of five volume & mass readings – each time adding

more and more liquid to the cylinder. 5. When you have finished five trials, pour the sugar solution back into the bottle from which it came.

0% SUGAR

5% SUGAR

10% SUGAR

15% SUGAR

20% SUGAR

TRIAL VOLUME MASS MASS MASS MASS MASS 1 20.0 mL 2 40.0 mL 3 60.0 mL 4 80.0 mL 5 100.0 mL

6. When you are finished testing the known solutions, repeat the above procedure with an unknown solution.

UNKNOWN TRIAL VOLUME MASS

1 20.0 mL 2 40.0 mL 3 60.0 mL 4 80.0 mL 5 100.0 mL

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Analysis: Get your computer and open up the excel program. We need to make 6 different graphs. We will only print two of those graphs

• Put the volume in column A (A1 label volume in mL)

• the mass of 0% sugar in column B (B1 label mass 0% in g)

• the mass of 5% sugar in column C (C1 label mass 5% in g)

• the mass of 10% sugar in column D (D1 label mass 10% in g)

• the mass of 15% sugar in column E (E1 label mass 15% in g)

• the mass of 20% sugar in column F (F1 label mass 20% in g)

• the mass of the unknown solution in column G (G1 label mass unknown in g)

• highlight the columns A and B – mass sure you enter numbers only – no units

• click insert – then scatter – then click the upper left hand choice

• under chart tools – design – click chart layout #3 (furthest right)

• find the line that represents your unknown and right click the line – format trendline – click display equation on chart

• Write the slope of the sugar solution in the chart

0% SUGAR 5% SUGAR 10% SUGAR

SLOPE

15% SUGAR

20% SUGAR UNKNOWN

SLOPE • Repeat the above procedure for columns C-G. Make sure to highlight only two columns. To do this,

highlight column A then hold the control button down while highlighting column C. • After writing down all the slopes, pick the sugar solution that has the slope closest to your unknown. • Only two graphs need printing: the sugar solution closest to your unknown and the unknown.

o click chart tools – layout – chart title – above chart

o enter in your title for your graph (DV as a function of IV)

o Use the following proportion to calculate % sugar in your unknown:

Your unknown: % sugar in your unknown: