How does it relate to your world Intro to Chemistry How does it relate to your world

Things to think about… How many ways does chemistry apply to your life? Of those ways, which holds the most merit? Why do I need to know chemistry?

What is Chemistry? The study of the composition of matter and the changes that matter undergoes Matter is anything that has mass and occupies space Affects ALL aspects of life and most natural events

Areas of Study Organic – study of all chemicals containing Carbon Inorganic – study of all chemicals not containing Carbon Biochemistry – study of the processes that take place in organisms Analytical – study that focuses on the composition of matter Physical – study that deals with the mechanism, the rate, and the energy transfer that occurs when matter undergoes change

Organic Chemistry ALCOHOL ETHER BENZENE

Inorganic Chemistry Calcium Carbonate CaCO3 Sodium Chloride NaCl Calcite Halite Quartz Calcium Carbonate Sodium Chloride Silicon Oxide CaCO3 NaCl SiO2

Biochemistry Plants!

Analytical Chemistry

Physical Chemistry

Pure v. Applied Pure chemistry – research for research’s sake Nylon Applied chemistry – research for a purpose Aspirin

The Scientific Method

Purpose Answers why we are doing the experiment

Research Research is needed to gain information on the purpose of the experiment This information will be used to form a hypothesis

Hypothesis Means educated guess This is a proposed answer to the problem developed in the purpose

Experiment An experiment tests your hypothesis The experiment will contain different variables Independent Variable – Variable that is changed Dependent variable – measured based on the changes of the independent variable Control – used as a comparison to measure results

Data Always record data in a clear, understandable way Use charts and graphs to show data whenever possible

Analysis and Conclusion Analysis is the collection of data from the experiment which should suggest a result The conclusions states the result of the experiment and whether or not the hypothesis was correct or incorrect

Define the Variables for the Ants Independent Variable = Dependent Variable = Control = Length of their legs Number of steps taken Regular Ant

Talk it out… How would I find the best basketball shoe? How would I know the best type of grass for an athletic field? How would I know which detergent cleans clothes the best?

Qualitative v. Quantitative Qualitative = qualities, properties, or descriptions Quantitative = numbers, measurements, or calculations Give me two examples of each

Accuracy v. Precision Accuracy – a measure of how close a measurement gets to the apparent or true value of whatever is measured Precision – a measure of how close a series of measurements are to one another

Por Ejemplo

Ejemplo dos

Ejemplo tres

Por Ejemplo

International System Giga G Billion 109 1,000,000,000 Mega M Prefix Symbol Meaning Multiply By: Giga G Billion 109 1,000,000,000 Mega M Million 106 1,000,000 Kilo k Thousand 103 1,000 Deci d Tenth 10-1 .1 Centi c Hundredth 10-2 .01 Milli m Thousandth 10-3 .001 Micro µ Millionth 10-6 .000001 Nano n Billionth 10-9 .000000001 International System

Measurements Length meter m Mass grams g Temperature Kelvin K Time Quantity Unit Symbol Length meter m Mass grams g Temperature Kelvin K Time Second s Amount of a substance Mole mol Electric Current Ampere A

Derived Units Quantity Unit Symbol Area Square meter m2 Volume Cubic meter or Liter m3 or L Density kilograms per cubic meter kg/m3 Pressure Pascal (kg/m*s2) Pa Energy Joule (kg*m2*s2) J Frequency Hertz (1/s) Hz Electric Charge Coulomb (A*s) C

Practice mm mg cg cm km Gg Mm ng mL kL millimeters milligrams centigrams centimeters kilometers Gigagrams Megameters Nanograms Milliliters kiloliters

The Estimated Digit In chemistry we will measure materials to an estimated digit An estimated digit is a magnitude smaller than the tool we are measuring with We can only go one magnitude because we want to be as accurate as possible

Practice 3.2 cm 2.35 cm 36.3 mL

Scientific Notation Written as the product of two numbers: a coefficient and 10 raised to a power Therefore: 602,000,000,000,000,000,000,000 Equals: 6.02x1023 Or:0.000000000775 Equals: 7.75x10-10

Significant Figures Includes all the digits that are known PLUS a last digit that is estimated when measuring Calculations are based on significant figures!!! Significant figures are based on a set of rules

Significant Figure Rules Every nonzero digit in a reported measurement is assumed to be significant Zeros appearing between nonzero digits are significant Left most zeros appearing in front of nonzero digits are not significant Zeros at the end of a number and to the right of a decimal point are ALWAYS significant

Significant Figure Rules Zeros at the right most end of a measurement that lie to the left of an understood decimal point are not significant if they serve as place holders to show the magnitude of the number, if zeros are at the right of a decimal point, they are significant Exact quantities have an unlimited amount of significant figures

Starting Number NO YES Infinite sig figs YES NO YES NO NO YES Is number counted? Infinite sig figs Does number have a decimal? YES NO Are zeroes at the front? YES All digits except leading zeroes Are there zeroes trailing? NO NO YES All numbers are sig figs All digits except trailers

Examples / Practice 3 (Rule 1) 123 m 5 (Rule 4) 9.8000 x 104 m 40506 mm 22 meter sticks 98000 m 3 (Rule 1) 5 (Rule 4) 4 (Rule 2, 3, 4) 5 (Rule 2) Unlimited (Rule 6) 2 (Rule 5)

On Your Own! 0.05730m 0.00073 143 8.750x10-2m 8765m 40.007 m 0.074m 1.072m 4 2 3 5

Adding and Subtracting The answer to an addition or subtraction calculation should be rounded to the same number of decimal places (not including sig figs) as the measurement with the least number of decimal places Ex. 12.52m + 349.0m + 8.24m = 369.76 Therefore: 369.76  369.8

Practice 8.3 m + 2.22 m 8432 m - 12.5 m 35.2 sec + 2547 sec 52 m – 0.0042 m 2.4526 m + 8.4 m 2.10 m - 0.070 m 1780 m + 0.08 m 53.6 g - 0.00056 g 10.5 m 8420 m 2582 sec 52 m 10.9 m 2.03 m 1780 m 53.6 g

Multiplying and Dividing Round the answer to the same number of sig figs as the measurement with the least amount of sig figs Ex. 7.55m x 0.34m = 2.567m2 Therefore: 2.567m2  2.6m2

Practice 18m2 8.3m x 2.22m 675m 8432m / 12.5 89700 sec 35.2 sec x 2547 53.6g / 0.00056 18m2 675m 89700 sec .22m2 .29 .15m2 20000m or 2x104m 96000m or 9.6x104m

Conversions Units can be converted from one to another using a conversion factor or a simple equation Chemistry using conversions for mass, volume, and parts

Conversion Factors

Conversion Steps Starting Unit Conversion Factors

Conversion Practice 250 kPa (253.35) 2.5 atm  kPa 2000 J (1672) 400 Cal  J 75 °F  °K 356 g  lbs 250 kPa (253.35) 2000 J (1672) 3.0x102°K (296) .784 g