HONORS CHEMISTRY SUMMER ASSIGNMENT Video A1: Honors Chemistry Website

HONORS CHEMISTRY SUMMER ASSIGNMENT Video A2: Laboratory Preparation

By the end of this video you should be able to… Identify and explain the use of laboratory equipment. Objectives

Beaker  Glass used to hold or heat solutions.  Although it has graduations, it is NOT USED FOR MEASUREMENT!

Erlenmeyer Flask  Cone like shaped glass used for heating and filtering solutions.  Although it has graduations, it is NOT USED FOR MEASUREMENT!

Graduated Cylinder  Measures volumes of liquids to nearest 0.01mL  The plastic rim is used to protect the glass from breaking if the cylinder is accidentally tipped over.

Burette/Buret  Used to dispense small amount of liquids. Read to nearest 0.01mL.  Read upside down!  More accurate than a cylinder.

Pipette  Plastic pipettes are only used to deliver small amounts of unmeasured solutions.  Graduated glass pipettes are very accurate way of delivering small amounts of liquids read to 0.01mL or better.

Volumetric Flask  The most accurate piece of glassware.  Measures liquids to a very specific volume.

Balance  Used to measure masses of substances to nearest 0.01g.  Can be “tared”.

Mortar and Pestle  Used to grind solids into smaller pieces.

Well Plate  Provides small places to test reactions on a microscale.

Bunsen Burner  Used to heat substances.  Follow all safety procedures given by instructor.

Clamp and Ring Stand  Used to hold beakers, thermometers, funnels, and other material in place when heating.

Crucible  Porcelain cup used to heat substances very hot.  Caution: porcelain gets very hot!

Evaporating Dish  Used to hold solutions while heating to evaporate them.

Funnel  Used with filter paper and a flask to filter and separate liquids from solids.

Graphs  The independent variable is the factor that you have control over and change yourself. It belongs on the x-axis.  The dependent variable is the factor being measured belongs on the y-axis.

Now you should be able to… Identify and explain the use of laboratory equipment. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video A3: Percent, Decimals, Fractions, and Estimating

By the end of this video you should be able to… Calculate simple decimal, percent, and fraction examples relating to chemistry calculations. Objectives

Decimals  To solve decimal calculations without a calculator:  Ignore the decimal and multiply normally first  Count the TOTAL number of decimal places in the numbers and ADD them back to my first answer 0.3 x 4 = 3 x 4 = 12 = 1.2 ignore decimal solve replace one decimal 0.2 x 35 = 2 x 35 = 70 = 7 ignore decimal solve replace one decimal 0.25 x = 25x 4 = 100 = ignore decimal solve replace 5 total decimals

Decimals This also works with division but you add places BEFORE the decimal based on the two number’s decimal DIFFERENCE: 24 / 0.4 = 24 / 4 = 6 = 60 ignore decimal solve replace one extra place before decimal 120 / 0.03 = 120 / 3 = 40 = 4000 ignore decimal solve replace two extra places before decimal 0.3 / = 3/3 = 1 = 100 ignore decimal solve replace 2 extra places before decimal

Percent  10% means move the decimal one places smaller.  10% of 356 is 35.6  10% of 400 is 40  20% can be solved by multiplying by 0.2 or by taking 10% twice.  20% of 500 =.2 x 500 = 100 or 10% is 50 times 2 = 100

Percent  All percent's can be done this way. But 50% is easy because it is half and 25% is a quarter or half of half.  50% of 50 is 25.  25% of 250 is half of 125 = 62.5

Estimating  x x x x  Simplify the numbers to 1-2 numbers each  25 x 2 x x 4 x 10  Find numbers that are easiest to calculate and reduce  (25 x 2 = 50 x 4 = 200 x 10 = 2000) x  2000 x = 6

Now you should be able to… Calculate simple decimal, percent, and fraction examples relating to chemistry calculations. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video A4: Scientific Method

By the end of this video you should be able to… Utilize and explain the steps of the scientific method. Classify measurements and observations as qualitative or quantitative. Classify measurements and observations as intensive or extensive. Objectives

The Scientific Method 1. Identify the Problem or Purpose 2. Collect Information 3. Form a Hypothesis Including a) Claim: Your intelligent guess b) Evidence: Examples relating to your guess c) Reasoning: Explanation of your guess 4. Create a Procedure 5. Record Observations 6. Analyze data/ Make Inferences 7. Draw Conclusions/Amend Hypothesis

Observation versus Inference  Observations use the senses. You observe what you can hear, smell, touch, hear or taste. Most students will have the same observations recorded.  Inferences are small conclusions you make based on your observation. Many students will generate different inferences.

Observations and Inferences

Observations Observations are made many ways. They can be either: Qualitative: appearance or behaviors: not measured Quantative: a mathematical description. and either Extensive: dependant on the amount of matter Intensive: dependant on type of matter

Qual or Quant and Intensive or Extensive? Rough or smooth Shiny or dull Large or small Kinetic energy

Now you should be able to… Utilize and explain the steps of the scientific method. Classify measurements and observations as qualitative or quantitative. Classify measurements and observations as intensive or extensive. Objectives

Now What?  Please practice problems in the summer assignment handout.  or chat me on Remind if you have

HONORS CHEMISTRY SUMMER ASSIGNMENT Video B1: Scientific Notation

By the end of this video you should be able to… Convert numbers into and out of scientific notation. Objectives

Scientific Notation What is the purpose for using scientific notation in science?

Scientific Notation M x 10 n M is between 1 and 10 n is the number of decimal spaces moved to make M

Rules 1. Find the decimal point. If it is not written, it is at the end of the number. 2. Move the decimal point to make the number between 1 and Place the number of space you moved the decimal in the n spot. 4. If you original number was above 1, the exponent is positive. If the number was smaller that 1, the exponent is negative.

Examples  is equal to  1.02x10 6  is equal to  7.89x10 -3  3.45x10 5 is equal to   1.23x10 -4 is equal to 

Now you should be able to… Convert numbers into and out of scientific notation. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video B2: Scientific Notation Multiply and Divide

By the end of this video you should be able to… Multiply and divide numbers in scientific notation without a calculator. Objectives

Scientific Notation in Mathematics Multiplication and Division: 1. Multiply or divide the base numbers. 2. When multiplying, add exponents. When dividing, subtract exponents. (8x10 5 )(2x10 3 ) = 16x10 8 or 1.6x10 9 (8x10 5 )/(2x10 3 ) = 4x10 2

Examples  (2x10 6 ) x (4x10 7 ) = 8x10 13  (1x10 8 ) x (5x10 -2 ) = 5x10 6  (8x10 8 ) / (4x10 4 ) = 2x10 4  (9x10 6 ) / (3x10 -2 ) = 3x10 8

Now you should be able to… Multiply and divide numbers in scientific notation without a calculator. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video B3: Scientific Notation Adding and Subtracting

By the end of this video you should be able to… Fix numbers that are not in proper scientific notation. Add and subtract numbers in scientific notation without a calculator. Objectives

Proper Scientific Notation The base number can only be between 1 and 10. If it is not in proper scientific notation form, change the base number to a number between 1 and 10 by moving the decimal. Count the movements.  If the base number got smaller, increase the exponent the amount of times you moved the decimal.  If the base number got larger, decrease the exponent the amount of times you moved the decimal.

Fix the following numbers  12x10 6 = 1.2x10 7  250x10 -3 = 2.50x10 -1  0.569x10 6 = 5.69x10 5  0.008x10 -2 = 8x10 -5

Scientific Notation in Mathematics Addition and Subtraction: 1. The exponents must be the same. Change your numbers to make this possible. 2. Add or subtract base numbers and do not change the exponent. * Remember: if the decimal move makes the base number smaller, the exponent increases. 5x x10 4 = 5x x10 5 = 5.3x10 5

Examples in Calculations  (3x10 6 ) + (4x10 7 ) = (.3x10 7 ) + (4x10 7 ) = 4.3x10 7  (5x10 8 ) + (5x10 9 ) = (.5x10 9 ) + (5x10 9 ) = 5.5x10 9  (2x10 5 ) - (4x10 4 ) = (2x10 5 ) - (.4x10 5 ) = 1.6x10 5  (2x10 6 ) - (4x10 4 ) = (2x10 6 ) - (0.04x10 6 ) = 1.96x10 6  When in doubt, you could take it out of scientific notation and then put it back in but that takes a lot of time.

Now you should be able to… Fix numbers that are not in proper scientific notation. Add and subtract numbers in scientific notation without a calculator. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video B4: Scientific Notation 2

By the end of this video you should be able to… Square, square root, and log numbers in scientific notation with out a calculator. Objectives

The Inverse of a Number in Scientific Notation If you need to take the inverse of a number in scientific notation, inverse the base number and multiply the exponent by -1.  (2x10 5 ) -1 = 0.5x10 -5 = 5x10 -6  1/(4x10 5 ) = 0.25x10 -5 = 2.5x10 -6

Scientific Notation Number Raised to a Power If a number in scientific notation is raised to a power, raise the base number to that power and multiply the exponents.  (2x10 -8 ) 2 = 4x  (4x10 3 ) 2 = 16x10 6 = 1.6x10 7  (2x10 -8 ) 3 = 8x10 -24

Square Root of Scientific Notation Numbers When taking the square root of a number in scientific notation, It is the same as raising it to the ½ power. Square root the base number and multiply the exponent by one half.   4x10 6 = 2x10 3   9x10 -2 = 3x10 -1   1.6x10 7 =  16x10 6 = 4x10 3

Logs for Chemistry Simple logs for chemistry require you to log a number with a base of 1. This means just reading the exponent!  log(1x10 -9 ) = -9  log(1x10 2 ) = 2  log(1x ) = -36

Now you should be able to… Square, square root, and log numbers in scientific notation with out a calculator. Objectives

Now What?  Please practice problems in the summer assignment handout.  or chat me on Remind if you have

HONORS CHEMISTRY SUMMER ASSIGNMENT Video C1: Intro to Metric

By the end of this video you should be able to… Identify metric units of measurement. Convert simple metric measurements. Objectives

Our country still uses an old system with non uniform measurements such as: fractions of an inch inches to a foot…. 3 feet to a yard…. 5.5 yards to a rod rods to a mile... 43,560 sq ft to an acre... But almost all other countries use the metric system, which is disadvantageous for us.

But we do use the metric for a few things: We buy cola in liters... We buy memory cards in bites… We run 10 km races... We swim in 25 meter pools... Why haven’t we switched entirely to metric?

Measuring Length in meters  When measuring a person we would use meters.  If we are measuring an ant, would meters still be feasible? What should we use?  If we are measuring the distance from your house to the school, what should we use?  Always pick a prefix with a value close to what you are measuring.

Simple Conversions  Convert 3,000 g to kg  Convert g to mg  Convert 250 cm to m  Convert 9000 mm to m  Convert 95L to mL  Convert 2500mL to L  Convert 2.0 pm to m  Convert 350 nm to m 3 Kg 0.7 mg 2.50 m 9 m mL 2.5 L 2.0x m 3.5x10 -7 m

Now you should be able to… Identify metric units of measurement. Convert simple metric measurements. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video C2: Metric Conversions

By the end of this video you should be able to… Convert numbers in metric measurements. Objectives

The Metric System  If a unit is getting larger (m  km) the number must get smaller. [If the unit gets smaller (m  cm) the number gets larger.]  Examples:  cm = km  mL = kL  mg = ug

More Examples  Convert 3,500 mg to kg  Convert kg to mg  Convert 250 cm to km  Convert 9000 mm to cm  Convert 95cL to mL  Convert 2500mg to pg  Convert 2.0 pm to mm  Convert 350 nm to mm kg 570 mg km 900 cm 950 mL 2.5x10 12 pg 2x10 -9 mm or 3.50x10 -4 mm

Now you should be able to… Convert numbers in metric measurements. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video C3: Temperature Conversions

By the end of this video you should be able to… Convert temperature measurements between Celsius and Kelvin. Objectives

Temperature Conversions  Notice that each scales is marked with BP and FP of water as well as absolute zero.  The degree size of Celsius is equal to Kelvin. Therefore we adjust only for zero points: °C = K – 273 K = ° C + 273

More Examples  Convert 0 ° C to K  Convert 25°C to K  Convert 100°C to K  Convert 0K to °C  Convert 298K to °C  Convert 273K to °C 273K 298K 373K -273C 25C 0C

Thinking in Celsius  -10° Celsius = frigid (14° F)  0° Celsius = cold (32° F)  10° Celsius = cool (50° F)  20° Celsius = comfortably warm (68° F)  30° Celsius = hot (86° F)  40° Celsius = very hot (104° F)  50° Celsius = Phoenix Hot (120°F)

Now you should be able to… Convert temperature measurements between Celsius and Kelvin. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video C4: Density

By the end of this video you should be able to… Calculate density Objectives

Density depends on:  Mass: the amount of matter an object contains. (This is different than weight, which is mass plus gravity)  Volume: The amount of space a substance occupies

How do we measure mass in the lab?  Electronic Balance

How can we measure volume?  l x w x h (regular solid)  ex. V = 1cm 3  Graduated cylinder (liquids)  Read bottom of MENISCUS  ex. V = 27.5 mL

Measuring Volume: Irregular Solid Water displacement method: 1. Measure initial volume 2. Measure final volume with object 3. The Difference is the volume of the object

Example What is the volume of the solid a. 46 mL b. 54 mL c. 8 mL d. 26 mL

Density  Ratio of mass of an object to its volume  Use density formula  Located on Table T

Example 1 What is the density of an object with a mass of 60 g and a volume of 2 cm 3 ? 60/2 = 30 g/cm 3

Example 2 An object has a volume of 800 cm 3 and a density of 13 g/cm 3. Find its mass. 13 = x g

Example 3: How to solve for mass or volume if density is not given: USE TABLE S Example: The volume of an aluminum sample is 100 cm 3. What is the mass of the sample? The density of aluminum on table S is 2.70g/cm = x g

Example 4 Determine the volume of an aluminum object with a mass of 40g. 2.70= 54 x 2.70 x = cm 3

Now you should be able to… Calculate density. Objectives

Now What?  Please practice problems in the summer assignment handout.  or chat me on Remind if you have

HONORS CHEMISTRY SUMMER ASSIGNMENT Video D1: Precision and Accuracy

By the end of this video you should be able to… Compare accuracy and precision. Objectives

Precision Versus Accuracy  Precision: reproducibility, repeatability  Accuracy: closeness to the correct answer 1. A student obtains the following data: 2.57mL 2.59mL 2.58mL 2.98mL Compare these pieces in terms of precision and accuracy.

Precision Versus Accuracy Describe these diagrams in terms of precision and accuracy: The first shows precision, not accuracy. The second shows accuracy, not precision.

In this classroom, what is more important: Precision or Accuracy?

Precision!  Due to lack of precise equipment and variable climates we will most likely not end up with accurate results. Therefore, we will focus on refining our lab skills and strive for precise results.

Now you should be able to… Compare accuracy and precision. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video D2: Significant Figures

By the end of this video you should be able to… Count the number of significant figures in a number. Objectives

Significant Figures  When scientists take measurements their equipment can measure with varying degrees of precision.  A scientists final calculation can only be as precise as their least precise measurement.  Count digits in your measured number to determine their level of precision.

Counting Significant Figures  All natural numbers 1-9 count once. 569 has 3SF3.456 has 4SF  The number zero is tricky…  Zeros always count between natural numbers: 109 have 3SF50089 has 5SF  Zeros before a decimal and natural number never count has 3SF has 4SF  Zeros after natural numbers only count IF there is a decimal present. 100 has 1SF100. has 3SF100.0 has 4SF

Now you should be able to… Count the number of significant figures in a number. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video D3: Rounding with Sig Figs

By the end of this video you should be able to… Round calculated numbers to the appropriate number of significant figures. Objectives

Adding/Subtracting Significant Figures  Remember: you can only be as precise as your least precise measurement. Therefore, when adding and subtracting, round your answer to the least number of DECIMAL PLACES.  = 7.61 = 7.6  = =  = = 34

Multiplying/Dividing Significant Figures  Remember: you can only be as precise as your least precise measurement. Therefore, when multiplying or dividing, round your answer to the least number of significant figures.  2.0 x 35.1 = 70.2 = 70.  5.11 x = = 504  72.1 / = = 23.1

More Examples Record the following with appropriate sig figs.  =  =  89.52/45.6 =  5 * 23 =  ( )/5.4 =  3.5( ) =

Now you should be able to… Round calculated numbers to the appropriate number of significant figures. Objectives

HONORS CHEMISTRY SUMMER ASSIGNMENT Video D4: Errors in the Lab

By the end of this video you should be able to… Calculate percent error. Objectives

Percent Error The measured value is a number from the lab data. The accepted value is a number published or given to you by a teacher. It doesn’t really matter which order you subtract in. You should take the absolute value. Therefore I usually subtract the big- small number. But ALWAYS DIVIDE BY ACCEPTED VALUE!

Examples: Calculate % Error  A student finds the density of a solid to be 5.6g/mL but the reference table states it should be 6.0g/mL.  ( )/6 *100 = 6.6%  A student finds the volume of a liquid to be 2.60L but the teacher says the correct answer is 2.45L.  ( )/2.45 *100 = 6.1%  The experimental value of the mass of a gas is 22.0L but the theoretical value is 22.4L.  ( )/22.4 *100 = 2%

Now you should be able to… Calculate percent error. Objectives

Now What?  Please practice problems in the summer assignment handout. I will be checking for evidence of your attempt in September.  or chat me on Remind if you have  See you soon!