Salt in Sand Lab
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Transcript Salt in Sand Lab
Salt in Sand Lab- Day 2
Mr. Forte & Ms. Shafai’s
Chemistry Classes
Step 1: Get your beakers &
Weigh beaker 2
Get beakers
from the tray
labeled with
your period
(make sure it is
yours)
Find mass and
record mass in
the data table
Beaker 2 ___ g
final mass
Mass of
salt (= to
Beaker 2
final
massbeaker 2
initial
mass)
____ g
Step 2: Weigh Beaker 1
Find mass
and record
mass in the
data table
Beaker 1
final mass
___ g
Mass of
____ g
sand
(=Beaker 1
final Beaker 1
initial- mass
of filter
paper
initial)
Step 3: Observations
Look at your beakers
Describe the contents in each
beaker in your lab notebook
Is there evidence that we have
a pure substance in one or
both beakers? (Write answers
in notebook)
Step 4: Calculate how much
lighter the sand is now
Look at Day 1 Sand Mass (line
e) and subtract Day 2 Final
Sand Mass from it.
Why is there a difference in the
mass of the sand? Where did
the rest of the mass go? (Write
answers to these questions in
notebook)
Step 5: Compare the mass
of sand lost to the mass of
salt
Calculate the difference
between the amount of sand
lost and the final mass of salt
(step 4-step1)
How close are these two
numbers? Where did the
difference in mass go?
Step 6: Calculate percentage
of salt in the original sand
sample
Take your final mass of salt and
divide it by our mass of sand
determined on day 1 (line e).
Write all calculations and label
each component in notebook
(DON’T FORGET SIGNIFICANT
FIGURES!)
Step 7: Clean Up
Dispose of filter and sand in
trash
Rinse both beakers with tap
water (make sure to get salt
out)
Return empty/washed beakers
to tray you got them from
Analysis of Data:
We must measure the
accuracy of our experimental
data
This measurement is called
“percent error”
This value is found by
comparing our experimental
data to a known/given value
Read handout about %
error
Look at and take turns reading
aloud from handout
What is the purpose of
calculating percent error?
Why do we use an absolute
value when calculating the
difference between your result
and the expected? (Write
answers in your lab notebook)
Calculate percent error
Expected results were 4.00 % salt
in sand
Calculate your percent error and
record in your notebook using
the following equation:
% error= I your result - 4.00% I * 100
4.00%
Congratulations- if you got
this far, you do not have
homework!