ANACHEM - PRELIM Flashcards
A step in the analytical process that involves
transforming the sample into something that
is appropriate for the analysis.
Sample Preparation
You are given a cube of pure copper. You
measure its density three times and the
values recorded are 7.97 g/cm, 9.01 g/cm,
9.36 g/cm. Copper’s accepted density is 8.96
g/cm. What is your percent error?
2%
(9.23±0.03 + 4.21±0.02)-3.26±0.06
Compute for the absolute certainty and %
relative uncertainty.
10.18±0.07; 0.7%
Process being used to obtain salt from ocean
water?
evaporation
What is 78,590 rounded to two significant
figures?
79000
Process that is commonly used to separate
colored substances from each other?
Chromatography
An apparatus in the laboratory that is
primarily used to guard against spillage
when pouring chemicals from one container
to another.
delivery funnel
Dylan is shooting dart pins at a target.
Which of the following demonstrates high
accuracy but low precision?
Dylan consistently hits around the target
but never hits the bullseye
Maya buys several boxes of test tubes. On
the package, it says that each box has 50 test
tubes. She opens the boxes and only one of
them has 50 test tubes inside, the other
boxes either have too many or too few. How
would you describe the box of test tube with
50 test tubes inside?
Accurate and precise
Method of separation being utilized for
mixture of iron and sulfur
magnetism
It is prepared by weighing out an appropriate
portion of a pure solid and dissolving it to a
measure volume of liquid.
stock solution
An experiment calls for measuring 30ml of
NaCl solution in a graduated cylinder. How
should the graduated cylinder be read?
Hunch down until your head is on the same
level as the table top, then look to make sure
the bottom of the meniscus is at 30ml
How close a measurement is to the true
value is
Accuracy
Which of the following is TRUE about
chromatography?
It is use to identify the nature of the
components of a given sample.
Simplify: 3.85 x 10^18 /7.35 x 10^36
5.24 x10^17
Good work practices in the laboratory
include
confining long hair and loose clothing
Why is volumetric flask considered as more
precise in measuring volume instead of a
beaker, Erlenmeyer flask etc.?
it only measures specific volume of liquid.
Simplify: 26.14/37.62 x 10^8(4.38 x 10^2)
3.04 x 10^10
Simplify: 9.24-1.342/2.3
3.43
Simplify: a^9b^14/(ab)^7
a^2b^7
Which of the following is TRUE about the
volume of solvent and moles of solute in a
diluted solution?
The increase in volume makes the solution
unsaturated while the moles of solute remain
constant.
Water can be separated from alcohol by
simple distillation because
They have different boiling points
Compute the absolute and % relative
uncertainty for the given and express the
answer to the correct number of significant
digits.
(91.3±1.0) (40.3±0.2)/ 21.2 ±0.943
174± 3; ±2%