• You need your lab
notebook!!
A note on assignments
• Late homework is worth 50%. I will not stamp
the date on it.
• BE ORGANIZED!! Keep your notebooks in one
place (on your shelf).
• Keep a separate notebook for each class.
• You are in 10th grade. It is YOUR responsibility
to complete assignments on time and to not
lose your things.
Studying
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Flashcards
Self quiz
Quiz a friend
Teach a friend from memory
Draw and label diagrams from memory
Rewrite notes
Make up practice quiz questions
Retaking a quiz
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Tuesday 8:10-9:00 pm
Thursday 7:00-8:00 pm
Call from desk, 2nd floor: 814
I will give you the higher mark
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Separation of a Mixture
Objectives: 1.
2.
Techniques: 1.
2.
Materials
16 Oct. 08
– (skip 5 lines)
• Procedure:
1.Find the mass…
Observations:
Separation of a mixture
Objective
• To separate a mixture of manganese
dioxide and sodium chloride.
• To determine the percent of each
obtained after the separation, and the
percent error.
Compounds
• manganese dioxide, MnO2, insoluble
black powder (manganese (IV) oxide)
• sodium chloride, NaCl, soluble white
crystals
Technique
• Filtration
• Evaporation
funnel
Filter paper
Stirring rod
Desiccator
(removes
water from a
sample)
Drying oven (removes
water from a sample
quickly)
Weighing
paper
beaker
Alcohol burner
Ring stand/ring
Spatula (for moving
powdered chemicals
from their containers)
Evaporating
dish
Procedure
1.
Find the mass of the 100 mL beaker on the
electronic balance.
2. Mass 2 grams of NaCl and 1 gram of MnO2
on weighing paper, and record their initial
masses. Mix them together in the beaker.
3. Add 20 mL distilled water to the NaCl and
MnO2 mixture. Swirl gently to mix, until all
the NaCl is dissolved.
Record a qualitative description.
How would you separate this mixture (and
record the mass of each compound after
separation)?
Equipment
• Beakers(2, 100 mL), electronic balance
(1), distilled water, graduated cylinder (1,
100 mL)
• NaCl (powder, 2g), MnO2 (powder, 1 g)
Homework 1
• Draw a cartoon of the SIX main steps
required to separate this mixture,
• and to find out the mass of each
compound collected at the end.
• Write a sentence to describe each of the
six steps, under each box of the cartoon.
• Due: Fri.
• Goals: Separate the manganese dioxide
from the NaCl.
• Find the mass of each compound after
the separation, and compare it to your
initial masses.
• Calculate your percent error.
your _ result  real _ result
%error 
100%
real _ result
Homework
• Due Thursday (with your cartoon)
• On a separate piece of paper:
1. Write the procedure for separating
these two compounds (don’t worry about
collecting the water) and calculating %
obtained/%error.
2.Write a list of materials and equipment
required (include how many of each).
A good procedure…
• Very specific – list every detail even if
you think it is obvious!
• In the correct order
• Give the name of each piece of
equipment you use
• Write when you will make observations
or take a measurement
• Describe how to do each calculation
• If you do not turn in this assignment,
you will not be allowed to participate in
lab.
• We will edit your procedures before
going to lab.
• Do your best…draw pictures if you have
a hard time writing sentences.
• Come see me for help!
Substance
Color
and
state
Solubility
in water
Separating
method
Product
from
Test for
presence
of product
manganese black
dioxide
powder
insoluble
filtration
residue on
the filter
paper
Reacts with
conc. HCl
acid and
the gas can
turn the
moist KIstarch
paper blue
sodium
chloride
soluble
evaporation solute
remained in
the
evaporating
dish
white
powder
Reacts with
AgNO3
solution to
produce
white
precipitate
Process of seporation
Process of Separation
Mixture
Mixture
Suspension
Suspension
Filtration
Filtration
Residue
– manganese
dioxide
Residue
--- Manganese dioxide
Solution
Solution
Reacts with HCl acid, turns
moist KI paper blue
Evaporation
Evaporation
Reacts with HCl acid ,turns moist KT-starch paper blue
Solute
Solute
–chloride
sodium
sodium
chloride
React with silver nitrate solution,
Reacts
with AgNO white
turning colorless solution turbid and 3
solution to form white
precipitate
Water
Water
mass of beaker (g)
original mass of NaCl (g)
original mass of MnO2 (g)
volume of water (mL)
mass of filter paper (g)
mass of evaporating dish (g)
total mass of evaporating dish and NaCl (first) (g)
total mass of evaporating dish and NaCl (second) (g)
difference between two masses (g)
mass of NaCl recycled (g)
total mass of filter paper and MnO2 (g)
mass of MnO2 (g)
percentage (%) of NaCl obtained
percentage (%) of MnO2 obtained
percentage of error (%)
•
Qualitative Observations:
a.
b.
c.
d.
e.
f.
Common Challenges
Add to your procedure to fix these
problems!!
When filtering
• How will you keep salt water from being
absorbed by your filter paper?
• Wet the filter paper with distilled water
from the wash bottle before filtering.
When evaporating
• How will you know when all the water is
evaporated?
• When the salt looks dry, mass the dish +
salt. Heat it a little longer, and mass it
again. Repeat, until the difference in
mass is less than 0.01 grams.
When finding final mass
• Scraping the NaCl from the evaporating
dish and the MnO2 from the filter paper
onto weighing paper will cause you to
lose a LOT of mass. How can you avoid
this?
• Mass the filter paper and evaporating
dish at the beginning. At the end, mass
the filter paper + MnO2 and the
evaporating dish + NaCl. Then, just
subtract!!
Calculations
• The procedure MUST show how to find
the final mass of NaCl and MnO2.
• Also describe how to calculate %
obtained (the percent of each at the end),
and % error.
Homework
• Write a final draft of your procedure in
your lab notebook (in the left column).
• Under “Materials,” list all the pieces of
equipment and compounds, including
how many/how much of each.
• Due Thursday, 30 October, in lab
• No procedure = no lab