ANALYTICAL CHEMISTRY LAB FINAL EXAM QUESTIONS AND
ANSWERS A+ GRADED. BUY Quality Materials!
What are the basic steps to using an analytical balance as well as the good and
bad practices?
Make sure the balance pan is aligned correctly.
Open the doors of the balance and then place a clean weigh boat or weighing paper on
the balance pan.
Close the doors of the balance.
Reset the tare to 0.
Remove the weighing paper or weigh boat from the balance and add the chemical.
Then place the weighing vessel back onto the balance and read its mass.
Continue to do this until you have the correct mass of chemical.
Good/bad practices:
-Do not place chemicals on the weighing pan directly to protect the balance from
corrosion.
-Clean up spills on the balance and do not allow chemicals to get into the mechanism
below the pan.
-Use a paper towel or tissue to handle the vessel that you are weighing, because
fingerprints will change its mass.
-The doors of the balance should be closed during the weighing process so that air
currents do not disturb the pan.
-Add chemicals to the weighing vessel or weighing paper outside of the balance to
prevent corrosion as well.
- Keep the doors of the balance closed at all times when weighing reagent as to preven
air currents from coming in.
What is the readability of a typical analytical balance?
0.01-0.1 mg
What is a decant?
to pour liquid off a solid, or perhaps, a denser liquid
What is a supernatant liquid?
liquid remaining above a solid after a precipitation
What is quantitative transfer?
Transferring the entire contents from one vessel to another, usually accomplished by
rinsing the first vessel several times with fresh liquid and pouring each rinse into the
receiving vessel.
What is a dessicant? Provide an example.
A drying agent. Ex: Drierite (calcium sulfate with a blue moisture indicator which was
used to dried the silver chloride), phosphorus pentoxide (P4O10), and calcium chloride
(CaCl2)
What is a dessicator?
ANSWERS A+ GRADED. BUY Quality Materials!
What are the basic steps to using an analytical balance as well as the good and
bad practices?
Make sure the balance pan is aligned correctly.
Open the doors of the balance and then place a clean weigh boat or weighing paper on
the balance pan.
Close the doors of the balance.
Reset the tare to 0.
Remove the weighing paper or weigh boat from the balance and add the chemical.
Then place the weighing vessel back onto the balance and read its mass.
Continue to do this until you have the correct mass of chemical.
Good/bad practices:
-Do not place chemicals on the weighing pan directly to protect the balance from
corrosion.
-Clean up spills on the balance and do not allow chemicals to get into the mechanism
below the pan.
-Use a paper towel or tissue to handle the vessel that you are weighing, because
fingerprints will change its mass.
-The doors of the balance should be closed during the weighing process so that air
currents do not disturb the pan.
-Add chemicals to the weighing vessel or weighing paper outside of the balance to
prevent corrosion as well.
- Keep the doors of the balance closed at all times when weighing reagent as to preven
air currents from coming in.
What is the readability of a typical analytical balance?
0.01-0.1 mg
What is a decant?
to pour liquid off a solid, or perhaps, a denser liquid
What is a supernatant liquid?
liquid remaining above a solid after a precipitation
What is quantitative transfer?
Transferring the entire contents from one vessel to another, usually accomplished by
rinsing the first vessel several times with fresh liquid and pouring each rinse into the
receiving vessel.
What is a dessicant? Provide an example.
A drying agent. Ex: Drierite (calcium sulfate with a blue moisture indicator which was
used to dried the silver chloride), phosphorus pentoxide (P4O10), and calcium chloride
(CaCl2)
What is a dessicator?
