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CHEMISTRY DISCLOSURE OVERVIEW
Homework packet (40 pts each)
• Bookwork and worksheets
• Practice packet with examples!!
Quizzes (10 pts each)
• Same as HW problems– different #s.
• Keep up with the HW → Free points
Labs (10 pts each)– about 3 each unit
Tests (100-120 pts each)– multiple choice and free response
Participation (100 pts per term)
• Be respectful of everybody else, you’ll be fine.
• Class parties 
• Be a jerk, lose 10 points OR class pop-quiz 
Office Hours/Help Sesh
• 7:00am-7:30am AND 2:25pm-3:30pm
Have parents email me with your name and period as subject
• If you get it done by tonight, I’ll let you drop your lowest
HW score at the end of the term 
REQUIRED MATERIALS
Binder + Paper
Pen, pencil,
Colored pen
Composition
Notebook
(graph paper)
Scientific Calculator
FEES
$6 Canvas
$5 Lab fee
LAB SAFETY RULES
1.
Safety Goggles must be worn at all times when
directed.
2.
No unauthorized experiments are allowed
3.
No horseplay is allowed.
4.
Keep work areas clean.
5.
Roll up loose, long sleeves.
6.
Tie back long hair
7.
Notify the teacher of any spills, broken glass
immediately.
8.
Never taste chemicals unless instructed to do so.
9.
Never return unused chemicals to the stock bottles.
10. Avoid contact of chemicals with the skin- wash with
soap and water if contact occurs, and notify the teacher.
LAB SAFETY RULES
11. Waft; don’t snort when testing for odors.
12. Do not place hot glassware directly on the counter.
13. Remember- hot glass looks like cool glass. Be careful.
14. Turn off burners when not in use.
15. When heating a substance, never look in the
container.
16. Stay in your lab group- do NOT wander around.
Remember we have the following safety items in the room:
A fire extinguisher
A fire blanket
An emergency shower and eyewash.
**Safety quiz at end of period.
**Tape your copy to front of lab notebook
TEXTBOOK CHECKOUT
• You will be given class time to work on
homework every class (if you’re good)
• It’s a good idea to bring your textbook to
class everyday
• Grab your student ID card and textbook and
get in line for checkout
UNIT 1. MEASUREMENTS & CALCULATIONS
CHAPTER 5
5.1 (Goal 7)
5.2 (Goal 1)
5.3 (Goal 3)
5.4 (Goal 5)
5.5 (Goal 6)
5.6 (Goal 2)
5.7 (Goal 4)
5.8 (Goal 8)
Scientific Notation
Units
Measurements of Length, Volume, and Mass
Uncertainty in Measurement
Significant Figures
Dimensional Analysis
Temperature Conversions
Density
Section 5.1: Scientific Notation
Universe clip
Powers of Ten clip
What is it?
• Writing very LARGE or SMALL numbers as a product of 1-10
and power of 10.
Ex.
25000 = 2.5 × 104
0.00135 = 1.35 × 10−3
45 𝑏𝑖𝑙𝑙𝑖𝑜𝑛 = 45,000,000,000 = 4.5 × 1010
1 𝑚𝑖𝑙𝑙𝑖𝑜𝑛𝑡ℎ = 0.000001 = 1 × 10−6
Why do we do it?
• More convenient way to write big or small numbers
• Makes number manipulation easier (×, ÷, x-1)
Section 5.1: Scientific Notation
In Class Problems (HW 5.1 - 3, 5, 69)
1. Express in scientific notation
𝑎. 7240 = 7.24 ×
103
𝑐. 5.408 = 5.408 × 100
𝑏. 0.0005519= 5.519 × 10−4
𝑑. 0.721 = 7.21 × 10−1
2. Express scientific notation as ordinary numbers
𝑎. 9.752 × 101 = 97.52
𝑏. 1.8 × 10−4 = 0.00018
𝑐. 5.321 × 104 = 53210
𝑑. 2.34 × 10−2 = 0.0234
Why do we do it?
• More convenient way to write big or small numbers
• Makes number manipulation easier (×, ÷, x-1)
Section 5.1: Scientific Notation
Multiplication
• Multiply front # and change to scientific notation
• Add exponents.
Ex.
104 ∙ 103 = 104+3 = 107
10−3 ∙ 104 = 10−3+4 = 101 = 10
−13
10−8 ∙ 10−5= 10−8+−5 = 10−8−5 = 10
9430 ∙ 106 = 9.43 × 103 ∙ 106 = 9.43 × 103+6 = 9.43 × 109
0.000046 ∙ 103 = 4.6 × 10−5 ∙ 103 = 4.6 × 10−5+3 = 4.6 × 10−2
(4.1 × 107 )(3.2 × 10−5 ) = 13.12 × 107 ∙ 10−5
3
= 1.312 × 101 × 107 × 10−5 = 1.312 × 101+7−5 = 1.312 × 10
Section 5.1: Scientific Notation
Division
• Divide front # and change to scientific notation
• Subtract exponents.
Ex.
−3
10
104
−3−4 = 10−7
= 104−3 = 101
=
10
104
103
10−8
−8−−7 = 10−8+7 = 10−1
=
10
10−7
0.0054
5400
5.4 × 10−3
=
5.4 × 103
5.4
=
× 10−3−3 = 1.0 × 10−6
5.4
2.3 × 108 2.3
8−4 = 0.38 × 104 = 3.8 × 10−1 × 104
=
×
10
6.0 × 104 6.0
= 3.8 × 103
Section 5.1: Scientific Notation
Inverse
• Inverse front number (1/front #)
• Switch sign of exponent
Ex.
1
1
1
−500
11
=
10
=
=
10
(10−4 )(10−7 )
10500
10−11
1
1
1
−4
−4
=
=
×
10
=
0.17
×
10
5.8 × 104
5.8
58000
= 1.7 × 10−1 × 10−4
= 1.7 × 10−5
1
1
1
3
=
=
×
10
4.8 × 10−3 4.8
0.0048
= 0.21 × 103
= 2.1 × 10−1 × 103
= 2.1 × 102
Section 5.1: Scientific Notation
In Class Problems (HW 5.1 - 8)
3. Manipulate these numbers to have your ending answer in scientific
notation
𝑎. 999 × 104 = 9.99 × 106
𝑏. 0.000045 × 10−3
= 4.5 × 10−8
(8.2 × 10−4 )
0
=
2.3
×
10
𝑐.
(3.6 × 10−4 )
(9.6 × 10−4 )
−2
=
3.2
×
10
𝑑.
(3.0 × 10−2 )
1
= 2.23 × 10−6
𝑒.
448000
1
𝑔.
(3 × 104 )(2 × 108 )
= 1.6 × 10−13
1
= 5 × 102
𝑓.
0.002
(104 )(10−6 ) (108 )
4
=
10
ℎ.
(102 )
Sections 5.2 and 5.3: Units of Measurement
Length, Volume, Mass, and Time
Scientific Observations
**Qualitative: Describes a property without using measurements
• The sky is blue.
• Fire is hot.
**Quantitative: Uses measurements to describe a property.
Measurements consist of two parts:
– number
– scale (unit)
Examples
• 20 grams
• 6.63 × 10–34 joule·seconds
Sections 5.2 and 5.3: Units of Measurement
Length, Volume, Mass, and Time
Systems of Measurement
English- only used in USA.
ex. Lbs, fl. oz, ft, in, etc.
Metric/SI (Systeme Internationale)used by rest of world
ex. Grams, liters, meters, centimeters.
VERY IMPORTANT TO PAY ATTENTION AND RECORD UNITS!!!
In SI, prefixes are used to change the size of the unit (base 10)
ex. Main unit of length = meter → used to measure height of a person
kilo-meter → distance between cities
micro-meter → thickness of human hair
SLC→Provo
72 kilometers
Ruler activity & Prefix chart
Sections 5.2 and 5.3: Units of Measurement
Length, Volume, Mass, and Time
In Class Problems (HW 5.2 – 9, 10, 70)
4. Match the prefix to the correct base 10 and abbreviation
a. centi-
106
μ
b. kilo-
10-1
M
c. deci-
103
n
d. micro-
10-3
c
e. mega-
10-9
k
f. nano-
10-2
d
g. milli-
10-6
m
Sections 5.2 and 5.3: Units of Measurement
Length, Volume, and Mass
**Length-Measurement of Distance (1D space)
ex. Convert 3.2 m to cm.
SI unit- meter
Conversion
1 𝑐𝑚
English unit- foot 1 in = 2.54 cm
3.2 𝑚
10−2
𝑚
= 3.2 × 102 𝑐𝑚
Volume-Measurement of 3D space
𝑉𝑜𝑙 = 1 𝑐𝑚 × 1 𝑐𝑚 × 1 𝑐𝑚
= 𝟏 𝒄𝒎𝟑 = 10−3 𝐿 = 𝟏 𝒎𝑳
𝑉𝑜𝑙𝑟𝑒𝑐𝑡 = 𝑙 × 𝑤 × ℎ
1 dm
SI unit- liter (L)
English unit- quart (q)
1 cm
Conversion
1 L = 1.06 q
ex. Convert 12 ML to L
1m
𝑉𝑜𝑙 = 1𝑚 × 1𝑚 × 1𝑚
= 1 𝑚3
1 dm
𝑉𝑜𝑙 = 1 𝑑𝑚 × 1 𝑑𝑚 × 1 𝑑𝑚
= 𝟏 𝒅𝒎𝟑 = 𝟏 𝑳
106 𝐿
12 𝑀𝐿
1 𝑀𝐿
= 1.2 × 107 𝐿
Sections 5.2 and 5.3: Units of Measurement
Length, Volume, Mass, and Time
**Mass- Measurement of Quantity of Matter
SI unit- **kilogram (kg)
Main unit- gram (g)
English unit- pound (lb)
Conversion
1 lb = 453.6 g
ex. Convert 68 kg to mg
DOES MASS=WEIGHT?
No! Mass is always the same!
**Weight depends on the pull of gravity
and is measured in Newtons (N)
--This is why you would weigh less on the moon,
But your mass would stay the same!
68 𝑘𝑔
103 𝑔
1 𝑘𝑔
1 𝑚𝑔
10−3 𝑔
= 6.8 × 107 𝑘𝑔
Time-Interval between to occurences
SI unit- second (s)
ex. Convert 17 years to seconds
Conversions
1 min = 60 s
365 𝑑𝑎𝑦𝑠 24 ℎ𝑟 60 𝑚𝑖𝑛
17 𝑦𝑟𝑠
1 hr = 60 min
1 𝑦𝑟
1 𝑑𝑎𝑦
1 ℎ𝑟
1 day = 24 hr
1 year = 365 days
60 𝑠
1 𝑚𝑖𝑛
= 536112000 𝑠
= 5.4 × 108
Sections 5.2 and 5.3: Units of Measurement
Length, Volume, and Mass
In Class Problems (HW 5.2 – 9, 10, 13, 70)
5. Fill in the blank.
1 kg = 103 g
1 cm = 10−2 m
1 g = 10−3 kg
1 m = 109 nm
1 cm = 101 mm
1 mm = 10−1 cm
1 mL = 10−6 kL
1 Mg = 1015 ng
1 kg = _______ g
1 cm = _______ m
1 g = _______ kg
1 m = _______ nm
1 cm = _______ mm
1 mm = _______ cm
1 mL = _______ kL
1 Mg = _______ ng
6. Convert between the SI Units
a. How many L in 460 mL?
1mL = 10-3 L
b. How many kg in 14 mg?
1 mg = 10-3 g, 1 kg = 103 g
a. How many cm3 in 45 mL?
1 mL = 1 cm3
10−3 𝐿
460 𝑚𝐿
1 𝑚𝐿
10−3 𝑔
14 𝑚𝑔
1 𝑚𝑔
1 𝑐𝑚3
45 𝑚𝐿
1 𝑚𝐿
= 0.46 L
1 𝑘𝑔
103 𝑔
= 45 𝑐𝑚3
= 1.4 × 10−5 kg
Sections 5.2 and 5.3: Units of Measurement
Length, Volume, and Mass
In Class Problems (HW 5.2 – 13, 18)
7. Convert 45 s to the following units
a. ns
1ns = 10-9 s
b. Ms
1 Ms = 106 s
c. μs
1 μs = 10-6 s
1 𝑛𝑠
10−9 𝑠
45 𝑠
1 𝑀𝑠
106 𝑠
1 𝜇𝑠
45 𝑠
10−6 𝑠
45 𝑠
= 45 × 109 ns = 4.5 × 1010 ns
= 45 × 10−6 Ms = 4.5 × 10−5 Ms
= 45 × 106 μs = 4.5 × 107 μs
8. Fill in the table
SI Unit
English Unit
Conversion(s)
Measuring Instrument
mass
kilogram, gram
pound
1 lb = 453.6 g = 0.4536 kg
balance/scale
volume
liter
quart
1 L = 1.06 q
graduated cylinder
length
meter
foot
1 in = 2.54 cm
meter stick
time
second
second
--------------------------
stop watch
Sections 5.2 and 5.3: Units of Measurement
Length, Volume, and Mass
How your prefix chart works (REVIEW)
Right column = multiplier
Left column= prefix
1 𝑀___
1 𝑘___
1 𝑑___
= 106 ____
= 103 ____
= 10−1 ____
1 𝑐___
= 10−2 ____
1 𝑐𝑚
= 10−2 m
1 𝑚___
1 𝜇___
= 10−3 ____
= 10−6 ____
1 𝑚𝑔
1 𝜇𝑠
= 10−3 g
= 10−6 s
1 𝑛___
= 10−9 ____
1 𝑛𝑚
= 10−9 m
Convert 5 mL to L
= 10−3 L
1 𝑚𝐿
5𝑚𝐿
−3 𝐿
___𝐿
10
___𝑚𝐿
1𝑚𝐿
= 5 × 10−3 L
1 𝑀𝑔
1 𝑘𝐿
1 𝑑𝑠
= 106 g
= 103 L
= 10−1 s
Sections 5.4 & 5.5: Uncertainty in Measurements and
Significant Figures
Every measurement has some degree of uncertainty
• usually due to visual estimates
from person to person and
precision of the measuring device
• A digit that must be estimated is
called uncertain.
20 cm
21 cm
What would you record the length of
this pencil to be?
a. 20.93 cm?
I would record it as
b. 20.94 cm?
20.94 cm
c. 20.95 cm?
Certain digits: 20.94
d. 20.96 cm?
Uncertain digit: 20.94
e. Any others?
Final reading looks like:
20.94±0.01 cm
# sig figs: 3+1=4
#𝑠𝑖𝑔𝑛𝑖𝑓𝑖𝑐𝑎𝑛𝑡 𝑓𝑖𝑔𝑢𝑟𝑒𝑠 = #𝑐𝑒𝑟𝑡𝑎𝑖𝑛 𝑑𝑖𝑔𝑖𝑡𝑠 + 1𝑢𝑛𝑐𝑒𝑟𝑡𝑎𝑖𝑛 𝑑𝑖𝑔𝑖𝑡
21
Sections 5.4 & 5.5: Uncertainty in Measurements and
Significant Figures
In Class Problem
9. Record the following measurements properly
4cm
5cm
For graduated cylinders, read
the bottom of the meniscus
35.0 ± 0.1 mL
36.4 ± 0.1 mL
4.72 ± 0.01 cm
Sections 5.4 & 5.5: Uncertainty in Measurements and
Significant Figures
Rules for Counting Sig Figs
•
•
•
•
1-9
Leading 0’s
Captive 0’s
Trailing 0’s
ALWAYS count
NEVER count
ALWAYS count
NEVER count
(unless with decimal)
All front numbers in scientific notation
are significant digits.
(another advantage to writing in scietific notation )
Ex. How many sig figs?
a. 453
a.
b. 0.00001534
b.
c. 0.084601
c.
d. 1200
d.
e. 1200.
e.
f. 1.20×103
f.
3
4
5
2
4
3
Sig Figs Calculating Rules (in packet)
Addition and Subtraction
-Number with lowest amount of digits
after decimal limits the answer’s sig figs
ex. How many sig figs in the answer?
22.102
300.956
18.3
−10.
+4.01
290.956 = 291
44.412 = 44.4
3 𝑠𝑖𝑔 𝑓𝑖𝑔𝑠
3 𝑠𝑖𝑔 𝑓𝑖𝑔𝑠
Multiplication and Division
-Number with lowest number of sig figs
limits the answer’s sig figs
ex. How many sig figs in the answer? 3.012
4.22 × 104
1.9 × 10−2
8.018 × 102
= 8.0 × 102
2 𝑠𝑖𝑔 𝑓𝑖𝑔𝑠
(3.012+4.2)
1.8456
7.2
1.8456
+4.2
7.212
→
= 3.9011703
= 3.9
2 𝑠𝑖𝑔 𝑓𝑖𝑔𝑠
Sections 5.4 & 5.5: Uncertainty in Measurements and
Significant Figures
In Class Problems (HW 5.5 – 24, 26-31, 33, 34)
10. How many sig figs are there? 11. How many sig figs will the answer have?
a.
b.
c.
d.
e.
f.
93750
586.200
0.0000007
5.01×10-8
π
3000001.0
8325
=1
4
a.
6
(2.5)(0.002)
1
(4.319 − 1.23)
=3
3
𝑏.
−7
∞- **natural (counting)
5.601 × 10
#’s don’t effect s.f. of
𝑐. 853.0 + 48.258 − 0.00005
8 answer
=4
12. Calculate the following with the correct sig figs.
= 1.35712 × 103
= 1.36 × 103
b.
(9.06×10−4 )
(3.0×10−2 )
= 3.02 × 10−2
= 3.0 × 10−2
c.
2
58500
= 3.41880341 × 10−5
a.
4.241 × 107 3.20 × 10−5
= 3 × 10−5
Sections 5.4 & 5.5: Uncertainty in Measurements and
Significant Figures
Accuracy vs. Precision
**Accuracy: How close measurements
**Precision: How close measurements
are to the true value
are to each other
PRECISE? ACCURATE?
Precise
Not Accurate
Precise
Accurate
Not Precise
Not Accurate
Not Precise
Accurate
ex. You measure the length of a 2.50 cm
pencil to be 2.54 cm. What’s the
Is there a way to calculate how accurate your
percent error?
measurement it??
2.50 𝑐𝑚 − 2.54 𝑐𝑚
Yes!! It’s called “Percent Error”
% 𝐸𝑟𝑟𝑜𝑟 =
× 100
2.50 𝑐𝑚
(% error=0 → 100% accuracy)
𝑽𝒂𝒍𝒖𝒆𝒕𝒓𝒖𝒆 − 𝑽𝒂𝒍𝒖𝒆𝒎𝒆𝒂𝒔𝒖𝒓𝒆𝒅
% 𝑬𝒓𝒓𝒐𝒓 =
× 𝟏𝟎𝟎
𝑽𝒂𝒍𝒖𝒆𝒕𝒓𝒖𝒆
=
− 0.04𝑐𝑚
× 100
2.50 𝑐𝑚
=
0.04
× 100
2.50 𝑐𝑚
= 1.60%
Packet Problems
Section 5.6: Dimensional Analysis
Why? A way convert between units --Did similar stuff in section 5.3
Goal: Use equivalence statements to write conversion factors
𝟏 𝒌𝒈 = 𝟏𝟎𝟑 𝒈
𝟏 𝒌𝒈
𝟏𝟎𝟑 𝒈
𝒐𝒓
𝟑
𝟏𝟎 𝒈
𝟏 𝒌𝒈
𝟏 𝒇𝒕 = 𝟏𝟐 𝒊𝒏
𝟏 𝒇𝒕
𝟏𝟐 𝒊𝒏
𝒐𝒓
𝟏𝟐 𝒊𝒏
𝟏 𝒇𝒕
𝟔𝟎 𝐬 = 𝟏 𝒎𝒊𝒏
𝟏 𝒎𝒊𝒏
𝟔𝟎 𝒔
𝒐𝒓
𝟔𝟎 𝒔
𝟏 𝒎𝒊𝒏
𝟏. 𝟎𝟔 𝒒 = 𝟏 𝑳
𝟏𝑳
𝟏. 𝟎𝟔 𝒒
𝒐𝒓
𝟏. 𝟎𝟔 𝒒
𝟏𝑳
ex. How many inches in 2.4 ft?
12 𝑖𝑛 = 28.8 𝑖𝑛
Plan: Ft → in
2.4 𝑓𝑡
1 ft = 12 in
1 𝑓𝑡
= 29 𝑖𝑛
How many feet in 50.0 cm?
Plan: cm → in→ ft
2.54 cm = 1 in
1 ft = 12 in
1 𝑖𝑛
50.0 𝑐𝑚
2.54 𝑐𝑚
1 𝑓𝑡
12 𝑖𝑛
= 1.6404 𝑓𝑡
How many in in 15 cm?
1 𝑖𝑛 = 5.90551 𝑖𝑛
Plan: in → cm 15𝑐𝑚
2.54 𝑐𝑚 = 5.9 𝑖𝑛
1 in = 2.54 cm
Convert 65 mph to km/s?
Plan: miles → km 1 mile = 1.6093 km
hours → min 1 hour = 60 min
1 min = 60 s
min → s
1.6093 𝑘𝑚
1 ℎ𝑟
1 𝑚𝑖𝑛
1 𝑚𝑖
60 𝑚𝑖𝑛
60 𝑠
= 1.64 𝑓𝑡
𝑘𝑚
𝑘𝑚
=
0.029
= 0.029056
(Packet Problems)
𝑠
𝑠
65
𝑚𝑖
ℎ𝑟
Section 5.6: Dimensional Analysis
In Class Problems (HW 5.6 – 14, 19, 39, 40, 43, 64, 65 and Packet Problems)
13. A baby is born to be 19 inches long.
Convert to m.
Plan: in → cm → m
1 in = 2.54 cm
= 0.48 𝑚
-2
1 cm = 10 m
14. How much money do I have if I
measure a row of quarters to be 55.0 cm
long?
Plan: cm → # quarters→ $
2.5 cm = 1 quarter
= $5.50
1 quarter = $0.25
15. Convert the following
Plan: mg → g → kg
4.3×10-6 kg
5.0 gallons to mL
Plan: gal → L → mL
1.9×104 mL
c.
3.0 m3 to mL
Plan: m3→ cm3 → mL
3.0×106 mL
d.
𝑔
210
𝑚𝐿
a.
4.3 mg to kg
b.
to
𝑙𝑏
𝑑𝑚3
Plan:
top: g→ lb
bottom: mL → cm3 → dm3
460
𝑙𝑏
𝑑𝑚3
Section 5.7: Temperature Conversions
• (°F) Fahrenheit- used by US and
England, elongated scale
• (°C) Celsius- used by Canada,
Europe and Scientists
• ( K) **Kelvin- SI unit for temp,
absolute scale (can’t go below 0K)
Celsius ↔ Kelvin
K = ℃ + 273
ex. Convert 55 °C to Kelvin.
𝐾 = 55℃ + 273 = 328
℃ = 𝐾 − 273
ex. Convert 267 K to °C.
℃ = 267𝐾 − 273 = −6℃
Section 5.8: Density
**What is it? Tells you how much matter is in a given volume
𝑑𝑒𝑛𝑠𝑖𝑡𝑦 =
𝑚
𝑚𝑎𝑠𝑠 (𝑔)
=
𝑣
𝑣𝑜𝑙𝑢𝑚𝑒 (𝑚𝐿 𝑜𝑟 𝑐𝑚3 )
How to determine density of an object?
• Mass• Volume-
measure on a **balance.
→liquid? Measure in a graduated cylinder
→perfect geometry? Measure dimensions
→imperfect or perfect? Measure displacement of water in a
graduated cylinder
𝑣𝑜𝑙𝑢𝑚𝑒𝑐𝑦𝑙𝑖𝑛𝑑𝑒𝑟 =
𝑣𝑜𝑙𝑢𝑚𝑒𝑟𝑖𝑛𝑔 =
68.0𝑚𝐿 − 64.0𝑚𝐿
29.0𝑚𝐿 − 19.0𝑚𝐿
= 10.0𝑚𝐿
= 4.0𝑚𝐿
𝑣𝑜𝑙𝑢𝑚𝑒𝑜𝑏𝑗𝑒𝑐𝑡 = 𝑣𝑜𝑙𝑢𝑚𝑒𝑓𝑖𝑛𝑎𝑙 − 𝑣𝑜𝑙𝑢𝑚𝑒𝑖𝑛𝑖𝑡𝑖𝑎𝑙
Section 5.8: Density
In Class Problems (HW 5.8 and Lab)
15. A student wants to find the density of a necklace that weighs 40.58 g. She puts it in
a graduated cylinder that has 10.1 mL water in it, and the new volume reads 12.2 mL.
What is her necklace made out of? (Use table 5.8 in book)
𝑚𝑛𝑒𝑐𝑘𝑙𝑎𝑐𝑒 = 40.58 𝑔
𝑣𝑛𝑒𝑐𝑘𝑙𝑎𝑐𝑒 = 12.2𝑚𝐿 − 10.1𝑚𝐿
𝑚
𝑑=
𝑣
= 2.1𝑚𝐿
40.58 𝑔
=
2.1 𝑚𝐿
𝑔
= 19.3238
𝑚𝐿
𝑔
= 19
𝑚𝐿
16. What is the density of a 20.2 mL sugar solution that weighs 28.89 g?
𝑚𝑠𝑜𝑙 = 28.89 𝑔
𝑣𝑠𝑜𝑙 = 20.2 mL
𝑑=
𝑚
𝑣
𝑔
28.89 𝑔
=
1.43019
=
𝑚𝐿
20.2 𝑚𝐿
𝑔
= 1.43
𝑚𝐿
17. The diameter of a silver sphere is 5.12 cm, and the weight is 723.85 g. What is the
density? % Error?
723.85 𝑔
𝑚
𝑔
𝑚𝑠𝑝ℎ𝑒𝑟𝑒 = 723.85 𝑔
4 3
3
4
=
70.3
𝑐𝑚
3
𝜋𝑟
3 𝑠𝑝ℎ𝑒𝑟𝑒 = 3 𝜋(2.56𝑐𝑚)
𝑑𝑠𝑝ℎ𝑒𝑟𝑒 5.12 𝑐𝑚
=
=
= 2.56 𝑐𝑚
2
2
𝑣𝑠𝑝ℎ𝑒𝑟𝑒 =
𝑟𝑠𝑝ℎ𝑒𝑟𝑒
𝑑=
𝑣
=
70.3 𝑐𝑚3
= 10.29658
𝑐𝑚3
𝑔
𝑑 = 10.3 3
𝑐𝑚
Section 5.8: Density
In Class Problems (HW 5.8 and Lab)
18. How much mass is in 18.6 mL of ethanol? (Density in table 5.8)
𝑚𝑒𝑡ℎ𝑎𝑛𝑜𝑙 =?
𝑣𝑒𝑡ℎ𝑎𝑛𝑜𝑙 = 18.6 𝑚𝐿
𝑑𝑒𝑡ℎ𝑎𝑛𝑜𝑙 = 0.785
𝑚∗
𝒅=
𝒗
𝑚 =𝑑∙𝑣
Multiply up
𝑚 = 0.785
𝑔
∙ 18.6𝑚𝐿
𝑚𝐿
= 14.6 𝑔 𝑒𝑡ℎ𝑎𝑛𝑜𝑙
𝑔
𝑚𝐿
19. How much volume is in 12.42 g of copper? (Density in table 5.8)
𝑚𝐶𝑢 = 12.42 𝑔
𝑣𝐶𝑢 = ?
𝑑𝐶𝑢
𝑔
= 8.96
𝑚𝐿
𝒎
𝒅= ∗
𝑣
Switch places
𝑚
𝑣=
𝑑
𝑣=
12.42 𝑔
𝑔
8.96 𝑚𝐿
= 1.39 𝑚𝐿
Section 5.8: Density
For your lab
GOALS/PROCEDURE
1. Measure the density of water
a) Weigh empty beaker
b) Add some amount of water– read volume to 0.1 mL
c) Weigh grad. cylinder + water
2. Measure density of unknown liquid
a) Same procedure with 10 mL grad. cyl.
b) SOME LIQUIDS HARMFUL TO BODY!! CAREFUL!!
3. Density of solid
a) Weigh object
b) Fill 100 mL grad. cyl. half way with water (Record volume (vinitial))
c) Add object (Record new volume (vfinal)
𝑣𝑜𝑙𝑢𝑚𝑒𝑜𝑏𝑗𝑒𝑐𝑡 = 𝑣𝑜𝑙𝑢𝑚𝑒𝑓𝑖𝑛𝑎𝑙 − 𝑣𝑜𝑙𝑢𝑚𝑒𝑖𝑛𝑖𝑡𝑖𝑎𝑙
𝑑=
𝑚
𝑣