About you! - PowerPoint PPT Presentation

1 / 70
About This Presentation
Title:

About you!

Description:

Title: Kinds of Chemistry Author: Paul S. Russo Last modified by: Paul Russo Created Date: 9/5/2001 4:24:56 PM Document presentation format: On-screen Show (4:3) – PowerPoint PPT presentation

Number of Views:188
Avg rating:3.0/5.0
Slides: 71
Provided by: Paul7317
Category:

less

Transcript and Presenter's Notes

Title: About you!


1
About you!
  • Largest groups by college Largest groups by
    major
  • Hobbies

2
Favorite music groups Lemme Know!
3
Why youre here (Fall 2011)
To get a degree, add a degree to all my experience
My parents will disown me if I dont earn a degree
To better myself, to become a lawyer
To get smart, to prove my parents wrong
To get an education in something I enjoy..
Math degree, so I can teach
To prove my parents wrong/
Make my parents proud
Better than being homeless
To party!
To get a good job
Last resort, didnt have a choice
Get wealthier
Something beautiful about studying ideas.
I value education
Secure future
To make a difference in peoples lives
To learn entrepreneurship
4
Syllabus summary Book
  • Russo (not me!) Silver book advisedor make a
    friend
  • Mastering Chemistry required
  • Alternate book advisable
  • Virtual book how I see things lecture
  • CEF study guides Factoids that are useful
    anything in them is fair game for exams!
  • Problems from book required
  • Fun books Cartoon Guide to Chemistry
  • P.W. Atkins Molecules

5
Syllabus Summary Homework Grades
3 varieties of homework Assigned-but-not-graded
(tied to unannounced quizzes in lecture)
Recitation Topics (tied to unannounced
quizzes) Mastering Chemistry on-line
assignments Approximate Grade Breakdown (see
actual syllabus) Quizzes 45 Graded Homework
(mostly MC on-line) 20 Midterms 20 (3
midterms, drop lowest) Final 30 of possible
points Early Performance Bonus 2.5 Exit
Tickets 3.5 (depends on group
performance!) Thats 120! Anything over 90
A. Anything over 80 B, etc.
ING13 an A grade means you can go BEYOND what
was taught.
6
There is much other stuff in the syllabus, so
please read it all. Thank you.
7
Announcements
  • This Friday, we will meet here in Lockett
    again.I am told we will have the TAs assigned
    soon so you can do stuff on Fridays. Yay.
  • We will try to get 450 quiz points by end of the
    course. We better start soon.
  • ING13 there is no study guide but ABNG problems.
  • The first MC assignment has been posted. Due
    Friday, Feb. 1, 1159 pm. Do it sooner!
  • We are about one day behinddont worry about it.

8
Whaddya knowits time to talk about chemistry in
some detail!
It is the subject of matter on a very fine scale.
Whats Matter?
9
Matter has mass and occupies space.
10
A doughnut is the same as a coffee cup (or a beer
mug).
Can anyone think of a way to make a material do
this?
A doughnut is the same as a coffee cup (or a beer
mug).
http//en.wikipedia.org/wiki/Topology
11
Hey.if we could change coffee cups into donuts,
we could do something dangerous and fun, like
make Wolverine claws!
Wolverine claws as we dangerously dream of them
http//www.youtube.com/watch?vLPmbGzQaOCsplaynex
t1listPLD8C557850FB35C59
http//www.youtube.com/watch?vLPmbGzQaOCsplaynex
t1listPLD8C557850FB35C59
Wolverine claws as we actually can make them
http//www.youtube.com/watch?vj0cs9j7HT-g
http//www.youtube.com/watch?vj0cs9j7HT-g
12
We need details about that matter definition has
mass and occupies space.
  • Mass how easy is it to accelerate the object. F
    ma
  • Acceleration change in speed with time
  • (dv/dt d2x/dt 2 for you Calculus experts)
  • Gravity provides a convenient, relatively
    constant,
  • acceleration F mg where g 9.8 m?s-2

13
Mass is measured indirectly
1 cm
1 cm
  • We could define one gram as the mass of one cubic
    centimeter (or one cc) of water.
  • Then see how much a spring is compressed with
    this mass on it under Earths gravity.
  • For a good spring, an object that compresses it
    2x more than one cubic cc of water must have 2
    grams of mass.
  • When you weigh something, you indirectly obtain
    its mass.
  • The thing really being measured is a force, which
    has other units (kg?m?s-2).
  • Well practice with compound units soon.

1 cm
14
Heres a picture of a spring scale.
If you look at old scales of good quality, they
will often proudly proclaim No Springs. Why?
http//www.medicalscale1.com/wp-content/uploads/20
11/01/spring-scale.jpg
It actually took awhile to find a spring scale on
the web---most scales today are digital. Probably
a piezoelectric transducer, not springs. I have
yet to see one that says no transducers.
15
How would you measure mass without gravity?
View from inside the space station.
http//spaceflight.nasa.gov/gallery/images/station
/
16
Matter Occupies SpaceWhats Space?What does it
mean to occupy space? In fact, for almost
anything you can name, most of the space is not
occupied!Before we can understand that, we have
to have ways to measure physical properties.
17
Space means volume.
  • Our favorite unit of length in chemistry is often
    the centimeter one-hundredth of a meter.
  • Volume is length x width x height, or cm3

1 cm
1 cm3 of water is one milliliter of water (one
one-thousandth of a liter, and a liter is almost
the same volume as a quart.)
1 cm
1 cm
Maybe we should write this as 13 cm3
18
Lets practice some volume and area calculations.
19
The next part of the lecture is brought to you
by the number
  • 2

Chapter 2 is about Quantitation, units and
energy.
20
How many creatures can count?
Recent studies..have uncovered new instances of
a counting skill in different species, suggesting
that mathematical abilities could be more
fundamental in biology than previously thought.
Under certain conditions, monkeys could sometimes
outperform college students. --Scientific
American, September 15, 2009
One monkey was able to choose between two sets of
identical objects, differing only by the number
of objects in the set. It was slightly less
accurate than college students at doing this, but
it was faster. This suggests the monkey was less
afraid of making mistakes. Because there was a
reward for performance (Kool Aid) the
non-chagrinned monkey moved on quickly to the
next round. Freshmen apparently were more
tentative about making mistakes. Probably a
lesson here for college students and
entrepreneurs. BTW, the blog after the article
is intriguing, tooa little bit funny and a
little bit sad.
Clever Hans, a German horse that could count,
ca. 1910.
There is a Clever Hans effect in Psychology,
traced to this animal. Some animals (people,
too?) Detect subtle body language cues and
respond according to those. That is how Clever
Hans could count. It was not a fraudthe animal
just sensed tension in the People answering the
questiononly if those people actually knew the
answer to it. Wikipedia article on Clever Hans
http//www.scientificamerican.com/article.cfm?idh
ow-animals-have-the-ability-to-count
http//www.scientificamerican.com/article.cfm?idh
ow-animals-have-the-ability-to-count
21
Words matter!
  • Precision is not Accuracy.

It is possible to be consistently wrong.
The difference between the right word and the
almost right word is really a large matter
it's the difference between a lightning bug
and the lightning.
Mark Twain (Samuel
Clemens)

http//www.metacafe.com/watch/44666/like_no_other/
22
What does this read?
The last number you report is always a
guess! The ? uncertainty is something like
1/10th of a decimal scale here that is ? 2
mph. Noise if the speedometer wiggles, it adds
even more uncertainty.
80
60
100
40
120
20
140
23
Noise is Normal!
A balance that reads 1.00053 to 1.00055 IS
working! A gauge that bounces around a bit IS
working!
(In fact, if it doesn't bounce, it might be stuck)
24
Some scales go by halves (thankfully)
How long is the pink line? Whats the ?
uncertainty here?
Drag divisors to split the scale by twos ?
25
This joke is from Prof. Pojman the guy with the
tie.
A class is touring the Museum of Natural History
on a field trip, and a kid asks the guide, How
old is this dinosaur? The guide replies, Sixty
million years and six months. The teacher is
astonished How can you tell the age so
precisely? I dunno, says the guide. When I
started working here six months ago, they told me
60 million years.
26
Significant Figuresjust keep it reasonable
(please!)
Wrong Right Why
1.867 2 3.867 1.867 2 4 Addition/Subtraction use least precise places
1.867 2.000 4 1.867 2.000 3.867 "
1.867 x 2 3.734 1.867 x 2 4 Multiply/Divide use smallest number of significant figures
1.867 / 2.000 1 1.867/2.000 0.9355 "
In this class, if its really a problem about
significant figures, you must get it exactly
right. If the problem is about something else,
just try not to look ridiculous.
27
Decimal points make things real.
2000 means 1900 to 2100
2000. means 1999 to 2001
2000.0 means 1999.9 to 2000.1
28
A problem can come when you use numbers ending in
zero in a sentence.
The meter reading was 2000.
What does THAT mean? Is the period there to end
the sentence or describe the numbers precision?
The meter reading was 2.000 x 103.
Unambiguous! It means between 1999 and 2001 or..
1.999 x 103 to 2.001 x 103
29
Announcements
We will NOT meet here on Friday. We dont know
exactly where we will meet yet, but. watch
for email. Surely, it will be near Choppin and
Williams Halls. Download attempt Recitation
Topics 1 from website.
30
Exponential (Scientific) Notation
  • Avogadros number
  • (the number of H2O molecules in 18.0 grams of
    water)
  • 602,000,000,000,000,000,000,000 6.02 x 1023
  • Age of universe in seconds (somebodys guess)
  • 300,000,000,000,000,000 s 3 x 1017
  • Learn to type exponents efficiently into your
    calculator! (The E or EEX button)

31
Exponent rules
m x m x m m3
2 x 2 x 2 23 8
(m3 )4 m12
(23 )3 29 83 512
23 x 24 27
m3 x m4 m7
These rules make sense when you write them out
term by term.
e.g. (23 )3 29 83 512 (2 2 2)3 (2
2 2) (2 2 2) (2 2 2) 29
32
You can nudge the tens powers, but usually we
dont leave it that way.
  • 3.1 x 1017 is the same as 31 x 1016
  • Handy if you must add 2 x 1016 to 3.1 x
    1017
  • 3.1 x 1017 2 x 1016 ltltltNudgeltltlt 31 x 1016 2
    x 1016
  • Result 33 x 1016
  • gtgtgtDe-Nudgegtgtgt 3.3 x 1017

33
The Exponent Rules Apply to Exponential Notation!
(6 x 1023) x (3 x 1013) 18 x 1036
Products Add Exponents
(6 x 1023) / (3 x 1013) 2 x 1010
Quotients Subtract Exponents
34
When/how do we use Exponential Notation
  • Use it when it is EASIER.
  • Your calculator has an E buttonlearn how it
    works

To code in Avogadros number (well see this
later) push 6-.-0-2-3- E-2-3.
35
Suppose a speeding ticket is 50 plus 10 x MPH
in excess of speed limit (60 MPH).
  • What is the range of costs for that speeding
    ticket if your car can go 125 MPH?

36
S.I. units were not chosen entirely by chemists.
The original idea of the meter was that there
would be 1 x 107 of them between the equator
and the North Pole.
Length Meter Mass Kilogram Time Second Te
mperature Kelvins Number of something Mole Elect
ric current Ampere Luminous intensity Candela
The units have an unusual history! On some other
planetdid you know there are billions of
planets?perhaps some other form of intelligent
life is using altogether different units. Here in
the USA, we still dislike the SI units. Even
most chemists prefer gram to kilogram, centimeter
to meter, etc.
37
Prefixesyes, you have to memorize them.
Prefix Example Example means
Nano Nanometer 0.0000000001 m or 10-9 m
Micro Microliter 0.000001 L or 10-6 L
Milli Milligram 0.001 gram
Centi Centimeter 0.01 meter
Deci Deciliter 0.1 liters ( 100 milliliters, by the way)
Deka Dekameter 10 meters
Hecto Hectogram 100 grams
Kilo Kilometer 1000 meters (0.6 miles, by the way)
Mega MegaHz 1000 cycles per second, once a very fast computer!
Giga GigaHz 1,000,000 106 cycles per second, now an OK computer (barely)
Smaller than
Larger than
38
You can do anything you want to both sides of an
equation.
Divide both sides by 5280 feet
Divide both sides by 1 mile
39
And you can multiple anything by 1 without
changing itexcept you might change the units.
A marathon is 26.4 miles. Whats that in feet?
X
Is the number of significant figures correct?
40
Announcements
MT1 should be available tonight. Unless you are
pre-educated, you should WAIT! Sign up for
EITHER no-calculator OR with-calculator. Yellow
notes template forms available. You MUST
relinquish these when you leave the testing
center. Schedule on website has been pushed
back a day or so.
41
Sample problems
  • How many clock cycles does a 3GHz Pentium
    computer go through in one day?
  • How many molecules of water in a nanogram of
    water?

42
The cost of disputing a grade.
  • In 1975, a promising young chemistry major drove
    42 miles from his new university to his old one
    to dispute a grade with the math department. If
    the 1967 Ford Galaxie got 17 miles per gallon,
    and if gasoline cost 0.54/gallon, what was the
    cost?

43
Lets do a basketball question.
  • A basketball court measures 94 x 50. Compute
    its area in square yards.

If you were the professor, how would you modify
this question for a quiz?
44
I married my lawnmower.
  • The lawnmower I am considering claims it can do
    1/3 acre without recharging.
  • My yard consists of 3 major segments measuring
  • (in feet) 70 x 30, 100 x 10 and 30 x 40. Can
    my wife use one of the new battery-powered lawn-
    mowers without recharging?

Convert is free on TigerWare? or use your
smartphone.
45
Lets give it a try. Easy way that works here.
Prim and proper way that always works.
46
Practice!
http//www.youtube.com/watch?vvjvJHsJD8ic
http//www.youtube.com/watch?vvjvJHsJD8ic
This scene is about 120 into the video
47
Many important properties have compound units.
Billiard ball floating in mercury.
  • Density is the mass per unit volume. For
    example, the liquid mercury in a thermometer has
    a density of 13.6 grams per cubic centimeter.
  • Units of density

http//www.zyra.org.uk/mercury3.htm
48
Why do we care?
  1. Density is an important, easily measured property
    that lets us gauge the purity of substances.
  2. Heavy stuff sinks, so that tells us what we might
    have to do to, say, clean up a hazardous waste
    site.

http//www.whistleblower.org/article.php?did18sc
id28 http//murray.senate.gov/hanfordcleanup/inde
x.cfm
The Hanford Nuclear Site 50 million gallons
(more?) of contaminated wastes on the beautiful
Columbia River. Pricetag to clean
40,000,000,000 4 x 1010. (I have seen much
higher estimates, too).
49
Or we could care just because density lets us do
fun stuff.
http//www.youtube.com/watch?vu19QfJWI1oQ
http//www.youtube.com/watch?vu19QfJWI1oQ
50
Another property with a compound unit force.
Defining physical relation Fm?a
51
Still more complex pressure
Defining physical relation P F/A
Force, Newtons
52
These arent the usual units of pressure here in
the USA!
  • 101,325 Pa atmospheric pressure 14.7 p.s.i.

Example most cars use 32 p.s.i. in their tires.
Whats that in Europe?
Harder (but fun) problems coming in the
Recitations.
53
Conversions
  • Figure out the smaller unit.
  • You will need a larger number of those.
  • Example
  • Q. How many deciliters in 10 Liters?
  • A. Deciliters is smaller, so you will need more
    of them. Ten deciliters for each liter times 10
    liters 100 deciliters.

54
Or, you can do it very prim and proper
55
Learn to line conversions out.
Start by putting what you want at the left.
Arrange conversion factors so as to cancel out
the unit you do not want!
56
Despite the metric system, you must still to be
able to convert between different unit systems.
  • Example the smallest MOPAR V8 engine of 1965
    was 273 cubic
  • inches. Today, wed quote that in liters, but
    how many liters?

Reason it out A liter is like one quart, a
cubic inch is like your thumb. Going from cubic
inches to liters should result in a smaller
number. 1 inch 2.54 centimeters (memorize!)
57
You may find it much easier at first to do these
problems one step at a time.
For example, just compute the conversion factor
for in3 to cm3 first.
Cube both sides
Now what?
58
What pressure do I exert on my feet?
English System
Metric System
  • P Force/Area
  • weight in pounds
  • /area in square inches
  • P Force/Area
  • mass x gravity
  • /area in square meters

59
BTW, if pounds in the English system really is a
unit of force, what is the English unit of mass?
http//hypertextbook.com/physics/foundations/syste
m-english/
http//en.wikipedia.org/wiki/Slug_(mass)
60
Problem estimate the volume of this room in
milliliters.
This will also teach us a bit about scientific
notation.
61
Mapping conversions that involve more than
multiplication division.
  • Example Centigrade to Fahrenheit

212
Slope 1.8
oF
32
100
oC
0
62
The centigrade scale is coarser centigrade
divisions are bigger. An 18-degree change in
Fahrenheit temperature is a 10-degree change in
Centigrade.
63
Kelvin temperature is just offset from
centigrade. The step size (degree size) is the
same, though, because the slope 1.
BTW, why 273.15 ???
K oC 273.15
64
Converting oC to oF in your head 
Double the oC temperature. Subtract 10. 
Add 32. 
65
Converting oF to oC in your head 
Subtract 32 Divide by 2 Add 10. 
66
Its worth remembering some temperatures.
16 oC 61 oF    July in Duluth February in Baton Rouge 
10 oC 50 oF  May in Minnesota January in Baton Rouge
98.6 oF 37 oC Body Temperature Summer in Dallas 
- 40 oF - 40 oC Winter in Minnesota, but hardly the coldest day there (record -60oF)
100 oF Rectal temperature of the cow 
77 oF 25 oC Room Temperature
77 K -196.15 oC -321 oF Liquid N2   
67
Now, lets turn to a study of temperature, energy
and power what ARE these?
But first, remember that Sony movie with the
bouncing balls.
http//www.metacafe.com/watch/44666/like_no_other/
68
Whiteboard or ELMO presentation of energy, to
include
  • W DE m?a?d
  • Q m ? C ? DT
  • calorie, Calorie and Joule
  • How crazy it is that this all goes back to
    choosing meter as our length and gram as the mass
    of 1 cm3

69
The heat capacity equation involves CHANGES in
temperature.
High heat capacity the material remains cool
about having heat added to it. Example
water. Low heat capacity the material gets hot
quickly if heat is added to it. Example gold.
Q heat added ?T temperature CHANGE
WHY does Gold have such a low heat capacity?
70
Heat Capacityor why it is actually not hot in
Baton Rouge in the summer
We mentioned that water had high heat
capacity. Water also forms the basis for
defining heat capacity. Heat capacity is how
much energy it takes to raise the temperature of
something by a certain amount.  Define  1
calorie the amount of energy required to raise
1.00 grams of water by 1.00 degree centigrade.
Note  a "food calorie" is actually 1000
calories!  SI unit of energy is the Joule 1
calorie 4.184 Joules
71
A CHANGE in temperature is the same in Kelvins as
in degrees centigrade!
T1 0oC 273K T2 10oC 283K ?T 10oC
10K
Define A calorie is the heat required to raise
1 mL (1 g) of water by 1 degree
Centigrade (e.g., by 1 Kelvin)
72
Stop here?
73
Assume you are mostly water, then estimate how
many calories it takes to raise your body
temperature from its normal 98.6oF to a fever
condition of 101oF. Convert this to Joules.
Write a Comment
User Comments (0)
About PowerShow.com