week 6 - chemistrythe graph • graph the data that was measured. graph every table as a separate...
Post on 06-Oct-2020
1 Views
Preview:
TRANSCRIPT
Week 6Unit 1 Matter (and Measurements)
Agenda
• EXP Reaction in a Bag
• Review: Sig Figs & Sci Not
• EXP Density (Modified Lab Report: Only Data, Graphing, and
Analysis
• Review: Metric System and Conversions
• Questions and Answers Session (Q/A)
Reaction in a BagExperiment – FULL Lab Report
Student Results
Part B• Create the 9 possible combinations as
CONTROL experiments to provide evidence to accept/reject hypothesis.
• Make observations.
• Reject/Accept your hypothesis.
• Answer Analysis questions to understand the data.
• C.E.R.
Results
Part B
• 9 – 10 combinations
• Divide and Conquer
Review Class Results
Evidence
Gas Temperature Change Color ChangeClick to add text
The Complete Reaction
Review & DepthSig Figs/ Sci Not
Math with Significant Figures
Addition & Subtraction Multiplication & Division
If it becomes tricky....go sci. not.
https://www.grandinetti.org/sig-fig-calculations
Scientific Notation
Math with Scientific Notation
Addition & Subtraction Multiplication & Division
EXP DensityVisually Representing and Analyzing
Quantitative Data
* What does the data tell us?*
Density
• Intensive property
• Mass of an object PER ml
• 1ml = 1 cm^3
Which has more mass?Which has more volume?
Which has a greater density?
Gathering Data
Measurements of a Liquid
Measurements of a Solid
Part A
1. Add one more row.
2. The first volume of water can be
"0".
3. Watch for significant figures
when you are reading
measurements tools AND doing
math with the measurements.
0
Add one more row here.
Part B: Solids
You will be measuring the volume of
the solid in 3 different ways.
1. Using a ruler.
2. Using the water displacement
method (1 L cylinder)
3. Using the water displacement
method with the overflow can (25 –
100 ml cylinder)
(One side)3 = Volume
The Overflow Can
Use a graduated cylinder to collect
the "overflow" that is as accurate as possible .
(between 25 ml– 100 ml)
What does the "overflow" measure?
The Math
Ultimately, you are
trying to get the mass
per ml so you can
compare different
substances/objects.
What is the unit for
density???/
Data Analysis
Water• What is the density of water?
• Besides 1 ml = 1 cc = 1 cm3, what does it also equals specifically for water?
4 Metals• What is the density of each
unknown metal?
• The results should be relatively consistent for all 3 methods of collecting volume of the metal.
• What is the identity of each unknown metal? (use the next slide)
Identify the Unknown
•Use the table to identify the unknown using YOUR data. (see the next slide for ACTUAL identities)
•If two metals have the same density, use otther
properties to make a claim.
•How do the metals/ alloys compare with water? What
would happen if they were mixed with water?
Part C: Analysis
Question 1: Identify the Unknown
A: Aluminum
B: Copper
C: Iron
D: Brass
Make corrections to this question in
red. Use the densities of these
metals for calculating percent error.
Percent Error
Part C: Analysis
In order to complete question 1, use this formula. The experimental value is the AVERAGE density of water that was calculated.
For Water: The accepted value for the density of water is 1.0 g/ml. Thus, for this example:
|0.990- 1.0|/1.0 * 100 = % error
Part C: Analysis
In order to complete questions 3 – 5, use this formula. The experimental value is your calculated values.
For Metal A: The accepted value for the density of Aluminum is 2.7 g/ml. Thus, for this example:
|3.031- 2.7|/2.7 * 100 = % error
Introduction to Graphs
Scatter Plots Line Graphs
Graphingy = mx + b
The Graph
• Graph the data that was MEASURED. Graph every table as a separate line on the SAME graph.
• NOTE: look at all the data points to determine the length of the axes and make intervals in units of 5 or 10.
• How do the metals compare to each other? To water?
• What does the slope signify?
Slope = y2 – y1/x2-x1
• What does it mean if the slope is steep?
Wh
at
wo
uld
go
he
re t
o f
oll
ow
ho
w s
lop
e
is f
ou
nd
us
ing
th
e d
en
sit
y f
orm
ula
?
What would go here to follow how slope is found using the density formula?
And the winner is.....
Which was the most accurate
method to measure volume of the
solids?
What is your evidence?
Questions and Answers (Q/A)
top related