chemistry september 9, 2014 dimensional analysis
TRANSCRIPT
![Page 1: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/1.jpg)
ChemistrySeptember 9, 2014
Dimensional Analysis
![Page 2: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/2.jpg)
Science Starter (2)
• Duration: 2 minutes• 1. What is the difference between
accuracy and precision?• 2. What is the difference between
a hypothesis, theory and law?
![Page 3: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/3.jpg)
OBJECTIVES (1)
• SWBAT – Convert units– Apply SI units– Apply Scientific Notation– Apply Significant Digits
![Page 4: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/4.jpg)
AGENDA (1)
• Do Science Starter (2)• Activities– Dimensional Analysis– SI units– Scientific Notation– Significant Figures
![Page 5: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/5.jpg)
ACTIVITY
![Page 6: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/6.jpg)
MEASUREMENTS (0.5)
• Measurements is a collection of quantitative data• Quantitative has amount while
qualitative does not
![Page 7: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/7.jpg)
PART 1 (2)• Using a ruler, measure the blueprint of
the apartment below• Measure using the feet and inches
side.• Write the measurement directly onto
the blueprint• You have 2 minutes• Work with your partner
![Page 8: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/8.jpg)
DIMENSIONAL ANALYSIS
• Convert from foot into meter• 1 foot = 0.3048 meter
![Page 9: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/9.jpg)
SETUP
![Page 10: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/10.jpg)
PART 2 (8)
• Model the Living Room• Guided Practice the Bedroom 1• Independently do the Bedroom 2,
Kitchen and Bathroom (you have 5 minutes)
![Page 11: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/11.jpg)
DIMENSIONAL ANALYSIS(CONT)• Definition: Math system using
conversion factors to move from one unit of measurement to a different unit of measurement. • Why we use it: Make doing
calculations easier when comparing measurements given in different units.
![Page 12: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/12.jpg)
PART 3
• Making the apartment design bigger for Mr. Giant• Multiply your answer in Part 2 by
100,000• Change into scientific notation to
make it easier to read
![Page 13: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/13.jpg)
SCIENTIFIC NOTATION• Use to write very large number and very
small number (more manageable)• Parts:–Before the decimal point = 1 number–After the decimal points = more than 1
numbers (can be optional)–Exponential number = the number of
places the decimal is moved
![Page 14: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/14.jpg)
EXAMPLE (3)
• STEP 1: –Multiply the number by
100,000• STEP 2: –Change into scientific notation
![Page 15: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/15.jpg)
SI UNITS• International System of Units (SI)• 7 SI base units– ampere (A) – measures electric current– kilogram (kg) – measure mass–meter (m) – measure length– second (s) – measure time– kelvin (K) – measure thermodynamic
temperature–mole (mol) – measure amount of substance– candela (cd) – measure luminous intensity
![Page 16: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/16.jpg)
SI PREFIXESPrefix Abbreviation Meaning
Exponential Notation
Number
tera T 1 trillion 1012 1,000,000,000,000
giga G 1 billion 109 1,000,000,000
mega M 1 million 106 1,000,000
kilo k 1 thousand 103 1,000
hecto h 1 hundred 102 100
deka da 1 ten 10 10
deci d 1 tenth 10-1 0.1
centi c 1 hundredth 10-2 0.01
milli m 1 thousandth 10-3 0.001
micro µ 1 millionth 10-6 0.000001
nano n 1 billionth 10-9 0.000000001
pico p 1 trillionth 10-12 0.000000000001
femto f 1 quadrillionth 10-15 0.000000000000001
![Page 17: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/17.jpg)
EXAMPLES (3)
• 1 m = 100 cm• 1 m = 10 dm• 1 m = 0.01 hm• 1 m = 0.001 km
![Page 18: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/18.jpg)
EXAMPLES (1)
• 1 g = 100 cg• 1 g = 10 dg• 1 g = 0.01 hg• 1 g = 0.001 kg
![Page 19: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/19.jpg)
PART 4
• Convert the living room measurements from cm to hm
• Use dimensional analysis• Remember: conversion factor is– 1 meter = 0.01 hm or 1 hm = 100 m– 1 meter = 100 cm
![Page 20: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/20.jpg)
PART 4
• Take 5 minutes to do the rest
![Page 21: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/21.jpg)
AREA
• PART 5–Find the area (A=wl) of Mr. Giant’s
apartment
![Page 22: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/22.jpg)
PERIMETER
• PART 6–Find the perimeter (P = 2(w+l))
of the apartment of Mr. Giant
![Page 23: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/23.jpg)
SIGNIFICANT FIGURES
• definition: a prescribed decimal place that determines the amount of rounding off to be done based on the precision of the measurement
• consist of all digits known with certainty and one uncertain digit.
![Page 24: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/24.jpg)
RULES FOR SIGNIFICANT FIGURES
![Page 25: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/25.jpg)
RULE 1
• nonzero digits are always significant–example: 46.3 m has 3
significant figures–example: 6.295 g has 4
significant figures
![Page 26: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/26.jpg)
RULE 2
• Zeros between nonzero digits are significant–example: 40.7 m has 3
significant figures–example: 87,009 m has 5
significant figures
![Page 27: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/27.jpg)
RULE 3
• Zeroes in front of nonzero digit are not significant–example: 0.009587 m has 4
significant figures–example: 0.0009 g has 1 significant
figure
![Page 28: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/28.jpg)
RULE 4
• Zeroes both at the end of a number and to the right of a decimal point are significant–example: 85.00 g has 4 significant
figures–example: 9.0700 has 5 significant
figures
![Page 29: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/29.jpg)
PRACTICE
• Do problems 1a – 1d on the Measurement Calculation Page
![Page 30: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/30.jpg)
MULTIPLICATION/DIVISION RULES
• Rules for using significant figures in multiplication and division–The number of significant figure for
the answer can not have more significant figures than the measurement with the smallest significant figures
![Page 31: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/31.jpg)
EXAMPLE
•Example: 12.257 x 1.162 = 14.2426234–12.257 = 5 significant figures–1.162 = 4 significant figures–Answer = 14.24 (4 significant figures)
![Page 32: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/32.jpg)
ADDITION/SUBTRACTION
• The number of significant figure for the answer can not have more significant number to the right of the decimal point
![Page 33: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/33.jpg)
EXAMPLE
• Example: 3.95 + 2.879 + 213.6 = 220.429–3.95 = has 2 significant figures after
the decimal points–2.879 has 3 significant figures after
the decimal points–213.6 has 1 significant figures after
the decimal points–Answer = 220.4 (1 significant figure)
![Page 34: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/34.jpg)
ROUNDING
–Below 5 – round down–5 or above - roundup
![Page 35: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/35.jpg)
EXACT VALUES
• has no uncertainty–example: Count value – number of items
counted. There is no uncertainty–example: conversion value – relationship
is defined. There is no uncertainty• do not consider exact values when
determining significant values in a calculated result
![Page 36: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/36.jpg)
WARNING
•CALCULATOR does not account for significant figures!!!!
![Page 37: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/37.jpg)
SCIENTIFIC NOTATION
RULES FOR CALCULATION
![Page 38: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/38.jpg)
RULE 1
• Exponents are count values
![Page 39: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/39.jpg)
RULE 2
• For addition and subtraction, all values must have the same exponents before calculations
![Page 40: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/40.jpg)
EXAMPLE
• Problem: 6.2 x 104 + 7.2 x 103
• Step 1: 62 x 103 + 7.2 x 103
• Step 2: 69.2 x 103
• Step 3: 6.92 x 104
• Step 4: 6.9 x 104 (Significant rule: can only have as many as the least significant figure to the right of the decimal)
![Page 41: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/41.jpg)
RULE 3
• For multiplication, the first factors of the numbers are multiplied and the exponents of 10 are added
![Page 42: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/42.jpg)
EXAMPLE
• Problem: (3.1 x 103 )(5.01 x 104)• Step 1: (3.1 x 5.01) x 104+3
• Step 2: 16 x 107
• Step 3: 1.6 x 108 (Significant rule: can only have as many as the least significant figure)
![Page 43: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/43.jpg)
RULE 4
• For division, the first factors of the numbers are divided and the exponent of 10 in the denominator is subtracted from the exponent of 10 in the numerator
![Page 44: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/44.jpg)
EXAMPLE
• Problem: (7.63 x 103) / (8.6203 x 104)• Step 1: (7.63 / 8.6203) x 103-4
• Step 2: 0.885 x 10-1
• Step 3: 8.85 x 10-2 (Significant rule: can only have as many as the least significant figure)
![Page 45: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/45.jpg)
PRACTICE
• Do problems 2a – 2d• Do problems 3a – 3d
![Page 46: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/46.jpg)
SCIENCE EXIT (2)
• Which measurement contains three significant figures?
• A. 0.08 cm• B. 0.080 cm• C. 800 cm• D. 8.08 cm
![Page 47: Chemistry September 9, 2014 Dimensional Analysis](https://reader035.vdocuments.net/reader035/viewer/2022062322/56649e155503460f94affa54/html5/thumbnails/47.jpg)
SCIENCE EXIT 2
• Given: (52.6 cm) (1.214 cm) = 63. 8564 cmWhat is the product expressed to the correct number of significant figures?
• 64 cm2
• 63.9 cm2
• 63.86 cm2
• 63.8564 cm2