Like this presentation? Why not share!

# 2 data 2011

## on Sep 11, 2010

• 419 views

unit 2 of the chemistryadventure series

unit 2 of the chemistryadventure series

### Views

Total Views
419
Views on SlideShare
419
Embed Views
0

Likes
0
0
0

No embeds

### Report content

• Comment goes here.
Are you sure you want to

## 2 data 2011Presentation Transcript

• Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
SI Units: Le SystemeInternationale
Unit 2: Data
Identify the 7 common SI units:
Kelvin
temperature
Ampere
k
current
second
s
time
A
mole
meter
amount
mol
m
distance
candela
brightness
cd
kg
kilogram
mass
Combined Units:
speed
acceleration
density
volume
Density formula:
1
• Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
Unit 2: Data
Density calculations
13.5 g of aluminum has a volume of 5 mL. Density?
What is the mass of 2 mL of aluminum?
• m = vd
• = (2 mL)(2.7 g/mL)
• = 5.4 g
divide
m
multiply
d
v
2
• Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
Unit 2: Data
Billion (109)
Giga (G)
2. Prefixes
Mega (M)
Million (106)
List the common unit prefixes and their abbreviations
kilo (k)
Thousand (103)
1
Hundredth 10-2
centi (c)
milli (m)
Thousandth (10-3)
micro (m)
Millionth (10-6)
3
nano (n)
Billionth (10-9)
• Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
Temperature
Unit 2: Data
When is Kelvin normally used and why?
Kelvin
Temp scale that cannot go below zero:
K to 0C:
25oC = ?K
K = oC +273
= 298 K
In many formulas: it is mathematically accurate.
0F to 0C:
°C= (°F - 32) × 5/9°F = ° C× 9/5 + 32
-40oC = ?0F
x9 = -360, /5 = -72, + 32 = -40 0F
-40oF = ?0C
-32 = -72, x5 = -360, /9 = -40 = -40 0C
4
4
• Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
Scientific Notationfor big and small numbers
Example:
Try some:
= 2.12 x 102
212
.0097
10,000
= 9.7x 10-3
= 1 x 104
602,000,000,000,000,000,000,000
Draw a line to make it between 1 and 10; count to decimal point.
Always 10x
Always 1-10
= 6.02x 1023
-2860
= -2.86 x 103
= 9.742 x 10-4
.0009742
5
• Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
Scientific Notation on your calculators: 2 methods
Enter 6.02 x 1023
For fancy calculators (like TI-83, etc)
For cheaper calculators that don’t do ()
Enter it all in parentheses- you’ll need them
Use EE button, no parentheses needed
Enter (6.02x10^23)
Enter 6.02E23
Example: what is (2 x 101)(1 x 101)?
Enter (2 x 10^1)(1 x 10^1)
Enter 2E1x1E1
= 200 or 2E2
Try this: (3 x 10-2) x (-4.2 x 10-4) = ?
Enter (3x10^-2)x(-4.2x10^-4)
Enter 3E-2x-4.2E-4
Negative, not subtract
Negative, not subtract
= -1.26 x 10-5 or -0.0000126
6
• Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
5. ConversionsA Sample Problem
You have \$7.25 in your pocket in quarters. How many quarters do you have?
What you are
given
3. Multiply using
Conversion factors
To get there
2. Write the units
you need to
Get to
4 quarters
29
= ___ quarters
X
7.25 dollars
dollar
Cancel your units to prove you did it correctly.
7
• 1. Units 2. Prefixes 3. Dens./temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
Convert 65 miles/hour to meters per second
• (1609 meters = 1 mile; 3600 seconds = 1 hour
What you are
given
3. Multiply using
Conversion factors
To get there
2. Write the units
you need to
Get to
1609 meters
1 hour
65 miles
x
x
meters
second
= 29.05
hour
1 mile
3600 seconds
Cancel your units to prove you did it correctly.
Slightly Harder Conversions
8
• Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
6. Significant Figures
1. When measuring
include the known digits plus one estimated digit.
Volume?
32.0 mL
9
• Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
Significant Figures: Guess which zero’s matter (L1 only)
number
why
# SIG. FIGS:
1. “non-zero numbers are always significant”
32
2
Never significant”
0.0323
3
3. “sandwiched zeroes are
always significant”
3.004
4
300
1
4. “trailing zeroes are only significant if there is a decimal place”
300.
3
5
300.20
.030690
Summary:
Keep if decimal present
dump
10
keep
• Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
Learning Check INCLUDE add subtract multiply divide add graph to formula slide
A. Which 2 answers contain 3 significant figures?
1) 0.4760 2) 0.00476 3) 4760
B. All the zeros are significant in
1) 0.00307 2) 25.300 3) 2.050 x 103
C. 534,675 rounded to 3 significant figures is
1) 535 2) 535,000 3) 5.35 x 105
> or = 5; round up
11
• 7. Percent Error
Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error
You measure your mass to be 120 lbs,
but in reality it is 150 lbs. What is your percent error?
Add images, perhaps a video, etc.
= 30 lbs/150 lbs x 100
= 20%
End data unit 
12