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CH110 Foundations of GENERAL, ORGANIC, & BIOCHEMISTRY CHEMEKETA COMMUNITY COLLEGE

CH110 Foundations of GENERAL, ORGANIC, & BIOCHEMISTRY CHEMEKETA COMMUNITY COLLEGE INSTRUCTOR: Dr. Jan Cammack http://newterra.chemeketa.edu/faculty/camj. 1 st Day Stuff. Who are you? Are you in the right place? GOB CTV Introduction Privacy waver Chemeketa Pipeline Course Web Page

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CH110 Foundations of GENERAL, ORGANIC, & BIOCHEMISTRY CHEMEKETA COMMUNITY COLLEGE

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  1. CH110 • Foundations of • GENERAL, ORGANIC, • & BIOCHEMISTRY • CHEMEKETA COMMUNITY COLLEGE • INSTRUCTOR: Dr. Jan Cammack • http://newterra.chemeketa.edu/faculty/camj

  2. 1st Day Stuff • Who are you? Are you in the right place? • GOB • CTV Introduction • Privacy waver • Chemeketa Pipeline • Course Web Page • Course Syllabus & requirements • Who am I? • Web CT Quizzes

  3. CH110 Recitation & Lab: Week 1 • Complete the prelab assignment for Lab Experiment 1: Burners & Flames • Homework problems will be due each week at recitation • Chpts 1(&2) problems due Thur

  4. Chapter 1:Measurement • Units of Measurement • Significant Figures • Conversion Calculations • Density

  5. Units of Measurement meter (m) 1 m = 1.09 yd liter (L) 1 L = 1.06 qt gram (g) 1 kg = 2.2 lb

  6. Matter • =The stuff things are made of. • (Air, water, rocks, etc..) • Matter has Mass and takes up space. • =The amount of stuff (in g’s) • (Bowling Ball > Balloon) Weight on earth. =Pull of Gravity on matter.

  7. Mass Vs. Weight How much would you weigh on another planet? http://www.exploratorium.edu/ronh/weight/

  8. Scientific notation • If a number is larger than 1 • Move decimal point X places left to get a number between 1 and 10. 1 2 3 , 0 0 0 , 0 0 0. = 1.23 x 108 • The resulting number is multiplied by 10X.

  9. Scientific notation • If a number is smaller than 1 • Move decimal point X places right to get a number between 1 and 10. 0. 0 0 0 0 0 0 1 2 3 = 1.23 x 10-7 • The resulting number is multiplied by 10-X.

  10. Examples • Write in Scientific Notation: • 25 = • 8931.5 = • 0.000593 = • 0.0000004 = • 3,210. = 2.5 x 10 1 8.9315 x 10 3 5.93 x 10 - 4 4 x 10 - 7 3.210 x 103

  11. Scientific notation 0.0144939 • 1.44939 x 10-2 = On Calculator 1.44939 (-) 2 EE 1.44939 E-2 x 10 Means x 10 Change Sign

  12. Measured & Exact Numbers • Exact Numbers = • from counting or by definition 12 coins per package 12 coins 1 package 1 package 12 coins = 12 coins 1 dozen coins 1 dozen coins 12 coins =

  13. Measured & Exact Numbers • Measured Numbers = • estimated using a tool All measurements contain some uncertainty. • We make errors • Tools have limits

  14. Significant figures Length of object is between 6.7 and 6.8 The next digit would be a guess.             If use 6.76 then have error of + 0.01cm

  15. Certain Digits Uncertain Digit Significant figures • Expresses accuracy & precision. • You can’t report numbers better than the method used to measure them. • 6.76 units = 3sig figures

  16. Significant figures • Sig Figs don’t depend on the decimal point. • 255 millimeters • 25.5 centimeters • 2.55 decimeters • 0.255 meters • 0.0255 decameters 3 Sig Figs

  17. Significant figures: Rules for zeros Leading zeros are notsignificant. 0.00421 3 sig figs Leading zero Captive zeros are significant. 4012 4 sig figs Captive zero Trailing zeros behind decimal are significant. 114.20 5 sig figs Trailing zero

  18. Significant figures: Rules for zeros • 32,000 • Are the 0’s significant? • 2 sig figs = • 3 sig figs = • 4 sig figs = • 5 sig figs = 3.2 x 104 3.20 x 104 3.200 x 104 3.2000 x 104 32,000.

  19. Significant figures: Rules for zeros • 1025 km • 2.00 mg • 0.00570 • 520 Four(Captive zeros are significant) Three(trailing zeros behind decimal are significant) Three(only trailing zero behind decimal is significant, leading zeros are not) Two(No decimal, zero assumed insignif)

  20. Rounding Write with 4 Significant Figures: 2.5795035 becomes 2.580 > 5 round up < 5 round down. 1st insignificant digit 34.204221 becomes 34.20

  21. Significant figuresand calculations • An answer can’t have greater significance than the quantities used to produce it. • Example • How fast did you run if you • went 1.0 km in 3.00 minutes? 0.3333333333 speed = 1.0 km 3.00 min = ?

  22. Simplified rules for significant figures • Multiplication & Division Problems: • Do calculations. speed = 1.0 km 3.00 min = 0.333333333 km min • Look at sig figs for each value in calculation. (Constants don’t count.) 3 sig figs 2 sig figs • Report answer with same sig figs as least significant value. = 0.33 km min • Round off as needed.

  23. Simplified rules for significant figures • Addition & Subtraction Problems: • Do calculations. Significant to .1 1.9 + 18.65 20.55 Significant to .01 • Look at least significant place for each value in calculation. • Report answer to least significant place. = 20.6 Significant to .1 • Round off as needed.

  24. Metric prefixes • Changing the prefix alters the size of a unit. • Prefix Symbol Factor (multiple) mega M 106 1,000,000 kilo k 103 1,000 deci d 10-1 0.1 centi c 10-2 0.01 milli m 10-3 0.001 100 1

  25. Conversion of units • Example:Metric Conversion • How many milligrams (mg) are in 5 kilograms (kg)? • Factor label method • Identify your conversions factors. 1 kg = 1 1000 g 1000 mg = 1 1 g 1000 g = 1 1 kg 1 g = 1 1000 mg

  26. Example:Metric Conversion How many milligrams are in 5 kilograms? • Identify what is to the problem. unique 5 kg = mg • Identify how you want the answer to look.

  27. Example:Metric Conversion How many milligrams are in 5 kilograms? • Multiply by conversion factors until units cancel. 5 kg 1 1000 g 1 kg 1000 mg 1 g = mg 5,000,000 • If the words work, the numbers will work.

  28. Example: English-Metric Conversion You have a pen of rats each with an average weight of 0.75 lb. How much rubbing alcohol will it take to kill ½ of the population if the LD50 is 5000. mg/kg ? • Identify your conversions factors. 1 kg Bw = 1 5000 mg Alc 1.0 kg Bw = 1 2.2 lb Bw 5000 mg Alc = 1 1 kg Bw 2.2 lb Bw = 1 1.0 kg Bw

  29. 5000. mgAlc 1 kg BW 1.0kgBW 2.2 lbBW Example: English-Metric Conversion You have a pen of rats each with an average weight of 0.75 lb. How much rubbing alcohol will it take to kill ½ of the population if the LD50 is 5000. mg/kg ? Identify what is unique to the problem. 0.75 lbBW = mgAlc 1704.545 1700 mg = 1.7 x 103 Identify how you want the answer to look.

  30. Density Mass Density = Volume • Water 1.0 Urine 1.01 - 1.03 • Air 0.0013 Bone 1.7 - 2.0 • Gold 19.3 Oil 0.8 - 0.9 1cc = 1 cm3 = 1 ml = 1 g water g cm3 g ml At 4 o C or

  31. Density calculation What is the density of 5.00 ml of serum if it has a mass of 5.230 gs? • d =m • V d =5.230 g 5.00 ml • = 1.05 g • ml

  32. Specific gravity density of substance g ml • Specific Gravity = density of reference g ml Reference commonly water at 4oC • Specific Gravity is unitless. • At 4oC, density = specific gravity.

  33. Specific gravity Hydrometer • Commonly used to test sugar in urine. • Float height will be • based on Specific Gravity.

  34. Density as a Conversion A liquid sample with a density of 1.09 g/mL is found to weigh 7.453 grams. What is the volume of the liquid in mLs? • Identify any conversion factors. • What is unique to the problem? 7.453 g 1 ml 1.09 g = ml 6.837614 = 6.84 ml • How should the answer look? 1.09 g 1 ml 1 ml 1.09 g

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