More Practice Lab Report Debrief Overall quality of lab reports was Problems Quad beam balances can measure 0001 g CalculationsShow Them Percent of NaCl First write the equation you are using ID: 534835
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Slide1
Dimensional Analysis
More PracticeSlide2
Lab Report Debrief
Overall, quality of lab reports was Slide3
Problems
Quad beam balances can measure
+-
0.001 g
Slide4
Calculations…Show Them
Percent of
NaCl
First write the equation you are using!
Slide5
Calculations…Show Them
Percent of
NaCl
Mass of sample = 1.573g
Mass of
NaCl
= 0.480g
Then, write each of the masses (including units!)
Slide6
Calculations…Show Them
Percent of
NaCl
Mass of sample = 1.573g
Mass of
NaCl
= 0.480g
Then plug in your values with units!Slide7
Calculations…Show Them
Percent of
NaCl
Mass of sample = 1.573g
Mass of
NaCl
= 0.480g
Show the calculated value & round to correct
s.f.Slide8
Error Analysis
Identify any factors that explain why your % recovery was more/less than 100%
EXPLAIN how
each factor affected your results.Slide9
Error Analysis - example
Error Analysis
Touching beakers with fingers
Not measuring properly
Not decanting fully
Poppy seeds in sand
The
analysis
is missing! Explain
how these factors affected your results!Slide10
Error Analysis – example better
Touching beakers with fingers
– touching the beakers with our fingers would have transferred oils from our fingers to the beaker, adding extra mass to our measurements. However, since our percent recovery was
less than 100%,
this really does not account for our error.Slide11
Error Analysis – example better
Not measuring properly/misuse of scale,
etc
Automatic F if I see this on a lab report!
If you didn’t measure properly the first time, REPEAT THE LAB!!Slide12
Error Analysis – example better
Not decanting fully
We may
not have decanted all of the liquid/poppy seeds from the sand. This resulted in some poppy seeds and water being left in the sample beaker. However, when we dried the sand on the hot plate, all of the water should have evaporated. Poppy seeds in the sand would have resulted in a higher mass for the sand, and therefore, a higher %recovery for sand (and lower % recovery for poppy seeds), however, this still would not account for a % recovery over 100%, unless we did not evaporate the water fully. Extra water mass would account for a %recover over 100%.Slide13
Words from
The
Jabberwocky
by Lewis Carroll
There
are 20
tumtum
trees (ttt’s) in the tulgey wood (tw) In each tulgey wood (tw) there is one frumious Bandersnatch (fB) There are 5 slithey Toves (sT’s) in 2 borogroves (bg’s) There are 2 mome raths (mr’s) per Jabberwock (J) There are 2 JubJub birds (JJb’s) in 200 tumtum
trees (
ttt’s
) There are 200 mome raths (mr’s
) in each
borogrove
(bg) There are 5 JubJub birds (JJb’s) per slithey Tove (sT)
If there are 5 frumious Bandersnathches (fB’s), how many Jabberwocks should there be?