1c units and measurement
TRANSCRIPT
![Page 1: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/1.jpg)
Units and Measurement
ChemistryMrs. Coyle
![Page 2: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/2.jpg)
A) SI Units, Scientific Notation, Measurement, Accuracy, Precision,
Error
![Page 3: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/3.jpg)
Math and UnitsMath- the language of ScienceSI Units – International System
MKSMeter mMass kgTime s
National Bureau of StandardsPrefixes
![Page 4: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/4.jpg)
SI Unit PrefixesName Symbolgiga- G 109
mega- M 106
kilo- k 103
deci- d 10-1
centi- c 10-2
milli- m 10-3
micro- μ 10-6
nano- n 10-9
pico- p 10-12
![Page 5: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/5.jpg)
Scientific Notation
M x 10n
M is the coefficient 1<M<1010 is the basen is the exponent or power of 10
![Page 6: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/6.jpg)
Other Examples:5.45E+6
5.45 x 10^6
![Page 7: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/7.jpg)
Numbers less than 1 will have a negative exponent.
A millionth of a second is:
0.000001 sec 1x10-6
1.0E-6 1.0x10^-6
![Page 8: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/8.jpg)
Limits of Measurement
Accuracy and Precision
![Page 9: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/9.jpg)
Accuracy - a measure of how close a measurement is to the true value of the quantity being measured.
![Page 10: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/10.jpg)
Example: AccuracyWho is more accurate when
measuring a book that has a true length of 17.0cm?
Susan: 17.0cm, 16.0cm, 18.0cm, 15.0cm
Amy: 15.5cm, 15.0cm, 15.2cm, 15.3cm
![Page 11: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/11.jpg)
Precision – a measure of how close a series of measurements are to one another. A measure of how exact a measurement is.
![Page 12: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/12.jpg)
Example: PrecisionWho is more precise when measuring
the same 17.0cm book?
Susan: 17.0cm, 16.0cm, 18.0cm, 15.0cm
Amy: 15.5cm, 15.0cm, 15.2cm, 15.3cm
![Page 13: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/13.jpg)
Example: Evaluate whether the following are precise, accurate or both.
Accurate
Not Precise
Not Accurate
Precise
Accurate
Precise
![Page 14: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/14.jpg)
Error
Error= experimental –accepted value
![Page 15: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/15.jpg)
Percent Error
% Error= |experimental –accepted| x100accepted value
![Page 16: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/16.jpg)
B) Significant Figures
![Page 17: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/17.jpg)
Significant Figures
The significant figures in a measurement include all of the digits that are known, plus one last digit that is estimated.
![Page 18: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/18.jpg)
Centimeters and Millimeters
![Page 19: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/19.jpg)
Graduated Cylinder - Meniscus
![Page 20: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/20.jpg)
![Page 21: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/21.jpg)
How many sig figs are there in a given measurement?
![Page 22: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/22.jpg)
Sig Figs
When the decimal is present, start counting from the left.
When the decimal is absent, start counting from the right.
Zeroes encountered before a non zero digit
do not count.
![Page 23: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/23.jpg)
How many sig figs?100 10302.00
0.001
10302 1.0302x104
![Page 24: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/24.jpg)
Sig Figs in Addition/Subtraction
The result has the same number of decimal places as the number in the operation with the least decimal places.
Ex: 2.33 cm+3.0 cm 5.3 cm
![Page 25: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/25.jpg)
Sig Figs in Multiplication/Division
The answer has the same sig figs as the factor with the least sig figs.
Ex: 3.22 cmx 2.0 cm 6.4 cm2
![Page 26: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/26.jpg)
Counting Numbers
Counting numbers have infinite sig figs.
Ex: 3 apples
![Page 27: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/27.jpg)
C) International System of Unitsand
Prefixes
![Page 28: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/28.jpg)
Base SI UnitsQuantity Unit SymbolLength meter mMass kilogram kgTemperature kelvin KTime second sAmount of Substance
mole mol
Luminous Intensity candela cdElectric Current ampere a
![Page 29: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/29.jpg)
Derived SI Units (examples)Quantity unit Symbol
Volume cubic meter m3
Density kilograms per cubic meter
kg/m3
Speed meter per second m/s
Newton kg m/ s2 N
Energy Joule (kg m2/s2) J
Pressure Pascal (kg/(ms2) Pa
![Page 30: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/30.jpg)
Units for Volume m3
cm3
dm3
L Liter
mL
1 dm3 = 1L
1cm3= 1mL
![Page 31: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/31.jpg)
Temperature
A measure of how hot or how cold an object is.
SI Unit: the kelvin ( K )
Note: not a degree Absolute Zero= 0 K
![Page 32: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/32.jpg)
Temperature Scales
![Page 33: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/33.jpg)
Celsius and Kelvin
K= oC + 273
![Page 34: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/34.jpg)
Farenheit and Celsius
oF= (1.8 oC ) +32
![Page 35: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/35.jpg)
Unit for Weight
1 Newton
1 N= kg m/s2
![Page 36: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/36.jpg)
Units for Energy Joule J
calorie 1 cal= 4.184 J
1 cal = quantity of heat needed to raise the temp of 1g of water by 1 oC.
![Page 37: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/37.jpg)
Note:
1 Cal = 1kcal =1000cal
![Page 38: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/38.jpg)
SI Unit PrefixesName Symbolgiga- G 109
mega- M 106
kilo- k 103
deci- d 10-1
centi- c 10-2
milli- m 10-3
micro- μ 10-6
nano- n 10-9
pico- p 10-12
![Page 39: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/39.jpg)
SI Unit Prefixes for LengthName Symbol Analogygigameter Gm 109
megameter Mm 106
kilometer km 103
decimeter dm 10-1
centimeter cm 10-2
millimeter mm 10-3
micrometer μm 10-6
nanometer nm 10-9
picometer pm 10-12
![Page 40: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/40.jpg)
D) Factor Label Method of Unit Conversion- Dimensional Analysis
![Page 41: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/41.jpg)
Factor-Label Method
Example: Convert 5km to m:
NEW UNIT5km x 1,000m =5,000m
km OLD UNIT
![Page 42: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/42.jpg)
Convert 7,000m to km
7,000m x 1 km = 7 km 1,000m
![Page 43: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/43.jpg)
Convert 2.45cs to s
2.45cs x 1 s = 0.0245s 100cs
![Page 44: 1C Units and Measurement](https://reader036.vdocuments.net/reader036/viewer/2022062412/577ccf261a28ab9e788eff93/html5/thumbnails/44.jpg)
Convert 55.00 km/h to m/s
55.00 km x 1000 m x 1 h___ = 15.28m/s h 1 km 3600 s