8 september 2011
DESCRIPTION
8 September 2011. Objective : You will be able to: collect and analyze data to determine the thickness of aluminum foil. demonstrate mastery of course expectations. Do now : Pick up a syllabus. Do now starts Monday. Agenda. Do Now Collect data for Al foil lab - PowerPoint PPT PresentationTRANSCRIPT
8 September 2011
Objective: You will be able to:a. collect and analyze data to
determine the thickness of aluminum foil.
b. demonstrate mastery of course expectations.
Do now: Pick up a syllabus.Do now starts Monday.
Agenda
I. Do NowII. Collect data for Al foil labIII. Aggregate class data and Dixon’s Q testIV. Discussion of significant figuresV. Course syllabus and expectationsVI. Unit 1 review Homework: Materials, signed syallabus, $10
Check Unit 1 summer assignment answers on the blog.
Class Aggregate Data
When you finish, enter your data into the spreadsheet.
Then, we’ll look for outliers.
Dixon’s Q Test for Outliers
x2 = closest value to suspectedx1 = suspected outlierxN-x1 = range of values
Qexp x2 x1
xN x1
Table of Critical Values
Discard if Qexp > Qcrit
Expectations
Email: [email protected]
Website: www.phascience.wordpress.com (for assignment sheets, some problem set answers, etc.)
Office hours: Tuesdays 3:30-4:30 pm and by appointment (before and after school) in Room 203
Office: Room 204
Materials
Three ring binder and loose leaf paper
Lab Notebook (available from Ms. Boiteau for $10)
Scientific calculator Pens or Pencils Chemistry Textbook
Chapter 1: Review
You are responsible for non-problem-solving concepts outlined in your chapter 1 notes
Measurement
SI Units:Quantity Name Symbo
lLength meter mMass gram gTime second stemperature kelvin Kamount of substance
mole mol
Prefixes: the important onesPrefix Symbo
lMeaning
kilo k 1000 (103)centi c 1/100 (10-2)milli m 1/1000 (10-3)micro μ 1/100,000,000
(10-6)nano (for wavelength)
n 1/100,000,000,000 (10-9)
Converting between orders of magnitude
Example 1: Express 3000. mL in liters.
Example 2: Express 0.0040 grams in milligrams.
Volume
Vmd
1 mL=1 cm3
Example The density of mercury, the only metal
that is liquid at room temperature, is 13.6 g/mL. Calculate the mass of 5.50 mL of the liquid.
Temperature Scales
K=oC + 273 0 K is the temperature at which… Don’t say “degrees Kelvin!”
Scientific Notation
a. 602,200,000,000,000,000,000,000 hydrogen atoms in a gram of hydrogen
b. Mass of one hydrogen atom: 0.000 000 000 000 000 000 000 001 66 g
c. 0.0005 secondsd. 4,000,000 gramse. 4.32x103 mLf. 9.32x10-5 cm3
g. 6.02x1023 atoms
An engineer was responsible for calculating amount of water that overflowed from a dam. He measured all of the water runoff going into the reservoir (1.2 million cubic feet per year), the rainfall (860 cubic feet per year), and the capacity of the reservoir (3.8 million cubic feet). He did some fancy calculations. He reported to his boss that the overflow from the dam would be 350,246.2544330 cubic feet per year.
What’s wrong here?
Determining Number of Significant Figures
A. Nonzero integers count as significant figures
Ex. Any number that is NOT zero (1, 2, 3, 4, 5, 6, 7, 8, 9)345597.2145.456
B. Zeros Leading zeros that come before all
the nonzero digits do NOT count as significant figures
Ex: 0.0025 has two sig. fig. The zeros are “leading” and do not count.0.230.00040.03564
Captive zeros are between nonzero digits and DO count as sig. fig.
Ex: 1.008 has four sig. fig. The zeros are captive and DO count.10,0041.0000061,000,000,000,000,567
Trailing zeros are to the right end of the number and DO count as sig. fig. if the number contains a decimal point.
Ex.: 100 has only one sig. fig. because the trailing zeros DO NOT have a decimal point.
Example: 1.00 has three sig. fig. because the trailing zeros DO have a decimal point.
1.000000 3,000,000 3.00000 30.00 300 300.
C. Exact numbers Any number found by counting has
an infinite number of significant figures.
Ex: I have 3 apples. The 3 has an infinite number of significant figures.50 people100 baseballs
Significant Figures
a. 5 cmb. 500 cmc. 5.0 gd. 5.000 mge. 500. Kf. 5.000x1010 atomsg. 505 desksh. 505,00.050 L
Addition/Subtraction Rules
Use the fewest number of digits to the right of the decimal place in the original numbers. Ex. 89.332 + 1.1 = 90.432 Round to
Multiplication/Division Rules
Round to the fewest number of significant figures present in the original numbers Ex: 2.8 x 4.5039 = 12.61092
Round to… Ex: 6.85/112.04 = 0.0611388789
Round to…
Exact Numbers
Have infinite significant figures 12 people, 5 atoms, etc. 1 inch = 2.54 cm
conversion factors are considered exact
Expressing Numerical Answers
EVERY TIME you write down a numerical answer in this class:a. Round it to the correct number
of significant figures.b. Put it in scientific notation if
at all possible.c. Include correct units.
Dimensional Analysis
How many seconds are there in 4.00 years?
How many milliliters are equal to 3.4x103 liters?
Homework
Check the answers to your chapter 1 summer assignment at
www.phascience.wordpress.com Come to class with questions!! Materials and $10
12 September 2011 Objective: You will be able to
demonstrate the Do Now procedure review unit 1 objectives
Do now:Label a piece of notebook paper “Week
of Sept. 12”Silently and on your own, with the use of
your notes and homework, answer the following questions:
Homework Quiz:1. I am five and a half feet tall and weigh 140 lbs.
Express my height in meters and my mass in kilograms.1 lb. = 453.6 g 1 m = 3.28 feet
2. The following procedure was used to determine the volume of an irregularly-shaped vase: The vase was weighed dry, then filled with water. The mass of the empty vase is 34.90 grams, and the full vase is 55.85 grams. The density of water is 0.9976 g/cm3. Calculate the volume of the vase in cm3.
Agenda
I. Homework quizII. Difficult volume conversion problemIII. Ch 1 questions?IV. Ch 1 problem set
Homework: Check chapter 2 summer assignment answers online
Ch 1 AP problem set: Thurs.
Announcements
Period 0 some “Special Wednesdays” Nov. 23 Dec. 7 Jan 25 Mar 21 Apr 11
Be a TA! See Mr. Moretti!
An average adult has 5.2 L of blood. What is the volume of blood in m3?
Questions about the Chapter 1 Homework?
Chapter 1 problem set
due Friday
Homework
Check chapter 2 summer assignment answers online
Ch 1 AP problem set: Thurs.