MEASURING SOLIDS Flashcards
is perhaps one of the
most fundamental concepts in science.
Measurement
It is a technique in which the properties
of an object are determined by comparing them to a standard.
Measurement
A highly precise
laboratory balance for
measuring mass
Analytical Balance
Used for exact
weighing applications
of small amounts of
material
Analytical Balance
Designed with an
enclosed measuring
pan
Analytical Balance
Chemicals are never _____ on the
weighing pan.
placed directly
A _____ is used under the chemical.
weighing boat, paper, or
bottle
When weighing material that can stain
(e.g., potassium permanganate), remember to
place a piece of _____ under the weighing pan
and push a large piece of paper up to the
balance to catch any material that falls off the
balance.
paper
Do not exceed the ____ of the balance.
maximum weight
limit
____the load on the pan as much
as possible.
CENTER
All objects or samples to be weighed
must be in _____ with the
room before a weighing can be
attempted.
thermal equilibrium
Never handle the item to be
weighed directly with your _____.
fingers
Immediately _____ any chemical spillage
on the pan, within the weighing
chamber, or in the work area surrounding
the balance.
clean
Always record
weighing to the
nearest
0.0001 g
Leave the sliding glass
doors ____, the
balance covered and
the area around it
clean.
closed
Weight Measurement
Check the balance pan to make sure it is _____ from any residue.
clean
and free
Weight Measurement
Press the _____. The digital display should
read 0.0000g
tare button
Weight Measurement
If the numbers on the digital display are
changing, ____ the lid to minimize the effect of
movements or air currents.
CLOSE
Weight Measurement
Place the receiver in the _____ of the weighing
pan.
center
Weight Measurement
Remove the _____ and
clean the balance pan.
receiver with the substance
is essential in setting the
properties of an object, it is useful for
determining identity and purity by comparing
values to a standard
Measurement
The word “measurement” comes from the Greek
word
metron,” which means “limited proportion.”
The metric system was developed in _____, revised,
and renamed as SI system (________ or International System of Units).
1790
System International
d’Unites
SI UNIT is used in almost all countries except
US
are
smaller in size and are
attached to the upper
portion of the vernier
caliper.
upper jaws
The most
prominent feature of a
vernier caliper. This is
designed to grip objects
firmly between them
for measurement
335573 | Spectrum Chemical, n.d.)
Lower jaws
the large
scale which runs along
the body of the vernier
caliper.
Main scale
a smaller
scale attached to the
main scale and can
move along the main
scale as the jaws are
opened or closed.
Vernier scale
used to measure
the depths of holes
Depth rod
used to fix the
position of the jaws once the
object is positioned properly
Lock screw
provides a
grip for the user to slide the
jaws easily and adjust the
position of the jaws and
depth rod while maintaining a
firm grip on the object
Thumb screw
top-Loading balance
has a capacity of up to
________
with the readability of
up to 3 decimal places
200 g (or up to 3.4 kg)
analytical balance Has a readability of four
decimal places (0.0001 g)
and has a capacity of up to
_____
320 g
Keep the balance _____
calibrated
Never touch analytical weights with _____. ______ from the skin can affect the
accuracy of the weight.
bare hands
Oils
Wear _______ provided
when manipulating the weights
gloves and use the forceps
The _____ should have no sharp edge,
and when possible, not have metal-to-
metal contact with the weights.
forceps
Ensure that
you weigh the
samples only
after closing
the ______.
weighing
chamber
doors
Keep the weighing
chamber clean to
prevent ________ of
samples and
______
cross-
contamination
erroneous
readings
