1 - 1 © Chemeketa Community College: Ch110 Foundations of General, Organic,& Biochemistry CH110...

1 - 1© Chemeketa Community College: Ch110 Foundations of General, Organic,& Biochemistry

CH110CH110Foundations ofFoundations of

GENERAL, ORGANIC,GENERAL, ORGANIC,

& BIOCHEMISTRY& BIOCHEMISTRYCHEMEKETA COMMUNITY COLLEGE

INSTRUCTOR: Dr. Jan Cammack

http://newterra.chemeketa.edu/faculty/camjhttp://newterra.chemeketa.edu/faculty/camj


11stst Day Stuff 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


CH110 Recitation & Lab: Week 1CH110 Recitation & Lab: Week 1

1. Complete the prelabprelab assignment for Lab Experiment 1Experiment 1: Burners & Flames

2. Homework problems will be due each week at recitation

– Chpts 1(&2) problems due ThurChpts 1(&2) problems due Thur


Chapter 1:Chapter 1:MeasurementMeasurement

Units of MeasurementUnits of Measurement

Significant FiguresSignificant Figures

Conversion CalculationsConversion Calculations

DensityDensity


MetricMetric

SISI

CommonCommon

ConversionsConversionsLengthLength

VolumeVolume

MassMass

Units of MeasurementUnits of Measurement

meter (m) 1 m = 1.09 ydmeter (m) 1 m = 1.09 yd

liter (L) 1 L = 1.06 qtliter (L) 1 L = 1.06 qt

gram (g) 1 kg = 2.2 lbgram (g) 1 kg = 2.2 lb


Matter has MassMass and takes up space.

Matter Matter =The stuffstuff things are made of.

(Air, water, rocks, etc..)

=The amountamount of stuff (in g’s) (Bowling Ball > Balloon)

WeightWeight on earth.

=Pull of Gravity on matter.


Mass Vs. WeightMass Vs. Weight

How much would you weigh How much would you weigh on another planet?on another planet?

http://www.exploratorium.edu/ronh/weight/


Scientific notationScientific notation

If a number is If a number is largerlarger than 1 than 1

•Move decimal point XX places leftleft to get a number between 1 and 10.

1 2 3 , 0 0 0 , 0 0 0.

•The resulting number is multiplied by 10XX.

= 1.23 x 108



If a number is If a number is smallersmaller than 1 than 1•Move decimal point XX places rightright to get

a number between 1 and 10.

0. 0 0 0 0 0 0 1 2 3 = 1.23 x 10-7-7

•The resulting number is multiplied by 10-X-X.


ExamplesExamplesWrite in Scientific Notation:

25 =

8931.5 =

0.000593 =

0.0000004 =

3,210. =

2.5 x 10 2.5 x 10 11

8.9315 x 10 8.9315 x 10 33

5.93 x 10 5.93 x 10 - 4- 4

4 x 10 4 x 10 - 7- 7

3.210 x 103.210 x 1033


x 10x 10

1.44939 x 101.44939 x 10-2-2 = =


+

-1

/

x

0

2 3

4 5 6

7 8 9

.

CE

EE

log

ln

1/x

x2

cos tan

1.44939 E-2

0.01449390.0144939

On Calculator On Calculator 1.44939 (-) 21.44939 (-) 2EEEE

Means Means x 10x 10 ChangeChange

SignSign


Measured & Exact NumbersMeasured & Exact Numbers

Exact Numbers =Exact Numbers = from counting or by definition

12 coins per package12 coins per package

12 coins 1 package

12 coins 1 package

1 package12 coins

1 package12 coins=

12 coins 1 dozen coins 12 coins

1 dozen coins 1 dozen coins

12 coins 1 dozen coins

12 coins=


Measured & Exact NumbersMeasured & Exact Numbers

Measured Numbers =Measured Numbers = estimated using a tool

• We make errors We make errors

• Tools have limitsTools have limits

All measurements contain some uncertaintyuncertainty.


Length of object is between 6.7 and 6.8The next digit would be a guess.

Significant figuresSignificant figures

If use 6.76 then have error of + 0.01cm



Expresses accuracy & precision.accuracy & precision.

You can’t report numbers better than the method used to measure them.

6.76.766 units = 33 sig figures

Certain Digits

UncertainDigit



Sig Figs don’t depend on the decimal point.Sig Figs don’t depend on the decimal point.

255 millimetersmillimeters

25.5 centimeterscentimeters

2.55 decimetersdecimeters

0.255 metersmeters

0.0255 decametersdecameters


Significant figures: Rules for zerosSignificant figures: Rules for zeros

0.00421 Leading zeroLeading zero

Captive zeros areare significant. 4012

Trailing zeros behind decimal areare significant.114.20

Captive zeroCaptive zero

Trailing zeroTrailing zero

Leading zeros are notare not significant.

33 sig figs

44 sig figs

55 sig figs


32,00032,000Are the 0’s significant?

22 sig figs =

33 sig figs =

44 sig figs =

55 sig figs =

3.2 x 103.2 x 1044

3.20 x 103.20 x 1044

3.200 x 103.200 x 1044

3.2000 x 103.2000 x 1044

32,000.32,000.



1025 km

2.00 mg

0.00570

520


ThreeThree (only trailing zero behind decimal

is significant, leading zeros are not)

FourFour (Captive zeros are significant)

ThreeThree (trailing zeros behind decimal

are significant)

TwoTwo (No decimal, zero assumed insignif)


Write with 4 Significant Figures:

2.5792.57955035035

RoundingRounding

1st insignificant digit1st insignificant digit

34.2034.2044221221 becomes 34.2034.20

becomes 2.5802.580

>> 5 5 round up

< 5 < 5 round down.

>> 5 5 round up

< 5 < 5 round down.


Significant figuresSignificant figuresand calculationsand calculations

An answer can’t have greater significance than the quantities used to produce it.

speed = 1.0 km 3.00 min

+

-1

/

x

0

2 3

4 5 6

7 8 9

.

CE

EE

log

ln

1/x

x2

cos tan

0.3333333333

= ??

ExampleExample How fast did you run if youwent 1.0 km in 3.00 minutes?


Simplified rules for significant figuresSimplified rules for significant figuresMultiplication & Division Problems:Multiplication & Division Problems:

• Do calculations.

•Look at sig figs for each value in calculation. (Constants don’t count.)

•Report answer with same sig figs as leastleast significant value.

•Round off as needed.

speed = 1.0 km 3.00 min

= 0.333333333 0.333333333 kmkm minmin

= 0.33 0.33 kmkm minmin

2 sig figs3 sig figs


Simplified rules for significant figuresSimplified rules for significant figuresAddition & Subtraction Problems:Addition & Subtraction Problems:

• Do calculations.

•Look at least significant placeplace for each value in calculation.

•Report answer to least significant place.

•Round off as needed.

1.9+ 18.65 20.55

= 20.6 = 20.6

Significant to .1

Significant to .01

Significant to .1


Metric prefixesMetric prefixesChanging the prefix alters the size of a unit.

Prefix SymbolPrefix Symbol Factor (multiple) 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

101000 1 1


Conversion of unitsConversion of units

Example:Example: Metric Conversion Metric Conversion How many milligrams (mg) are in 5 kilograms

(kg)?

1 kg1 kg = 1 = 11000 g1000 g

1000 g1000 g = 1 = 11 kg1 kg

1 g 1 g = 1 = 11000 mg1000 mg

1000 mg1000 mg = 1 = 11 g1 g

Factor label methodFactor label methodIdentify your conversions factors.


• Identify what is to the problem.

• Identify how you wantwant the answer to look.

5 kg5 kg = mg= mg

Example:Example: Metric Conversion Metric Conversion How many milligrams are in 5 kilograms?


• Multiply by conversion factors until units cancel.

• If the words work, the numbers will work.

5 kg5 kg

11

= mg= mg1000 g1000 g

1 kg1 kg

1000 mg1000 mg

1 g1 g

5,000,0005,000,000

Example:Example: Metric Conversion Metric Conversion How many milligrams are in 5 kilograms?


Example: English-Metric ConversionExample: English-Metric Conversion

You have a pen of rats each with an average weight of 0.75 lb0.75 lb. How much rubbing alcohol will it take to kill ½ of the population if theLD50 is 5000. mg/kg ?

• Identify your conversions factors.Identify your conversions factors.

1 kg Bw1 kg Bw = 1 = 15000 mg Alc5000 mg Alc

5000 mg Alc5000 mg Alc = 1 = 11 kg Bw1 kg Bw

1.0 kg Bw1.0 kg Bw = 1 = 12.2 lb Bw2.2 lb Bw

2.2 lb Bw2.2 lb Bw = 1 = 11.0 kg Bw1.0 kg Bw


0.75 lbBW0.75 lbBW

Example: English-Metric ConversionExample: English-Metric Conversion

You have a pen of rats each with an average weight of 0.75 lb0.75 lb. How much rubbing alcohol will it take to kill ½ of the population if theLD50 is 5000. mg/kg ?

1.0 kgBW

2.2 lbBW

5000. mgAlc

1 kg BW= mgAlc 1704.5451704.545

1700 mg1700 mg = 1.7 x 10= 1.7 x 1033

Identify what is uniqueunique to the problem.

Identify how you wantwant the answer to look.


DensityDensity

Water 1.0Water 1.0 UrineUrine 1.01 - 1.031.01 - 1.03

AirAir 0.0013 0.0013 BoneBone 1.7 - 2.01.7 - 2.0

GoldGold 19.3 19.3 OilOil 0.8 - 0.90.8 - 0.9

Density =Density = MassMass

VolumeVolume

1cccc = 1 cmcm33 = 1 mlml = 1 gg water 1cccc = 1 cmcm33 = 1 mlml = 1 gg water

g g

cmcm33

g g

mlmlor AtAt 4 4 oo C C


Density calculationDensity calculation

What is the density of 5.00 ml5.00 ml of serum if it has a mass of 5.230 gs5.230 gs?

= 1.05 = 1.05 g g mlml

d =d = mm V V

d =d = 5.230 g5.230 g 5.00 ml5.00 ml


Specific gravitySpecific gravity

Specific Gravity =Specific Gravity = density of substance g

mldensity of reference g

ml

ReferenceReference

commonly commonly water at water at

44ooCC•Specific Gravity is unitlessunitless..

•At 44ooCC, density = specific gravity.density = specific gravity.


Specific gravitySpecific gravity

•Commonly used to test sugar in urine.

Hydrometer

•Float height will be based on Specific

Gravity.


Density as a ConversionDensity as a ConversionA 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?

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?

1.09 g1.09 g1 ml1 ml

1 ml1 ml1.09 g1.09 g

• Identify any conversion factors.

•How should the answer look?

7.453 g7.453 g = ml= ml

• What is unique to the problem?

1 ml1 ml1.09 g1.09 g

6.8376146.837614 = = 6.846.84 ml ml

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