CHEM 101L UNC FINAL QUESTIONS AND ANSWERS
If a flammable substance in a beaker should catch fire while you are working but
the flames are relatively contained, what should you do to extinguish the flame?
What should you not do?
DO: Use the chemical fire extinguisher from the lab. Pull the pin, aim the nozzle to the
beaker, and pull the lever.
DO (Best, simplest): Turn off the heat source immediately and use a watch glass to
cover the beaker.
DON'T: Use water from the nearest sink to douse the flame.
How many times should you read the label on a reagent container and compare it
with the lab manual?
At least twice each time you remove material from the container.
While weighing out a reagent for use in an experiment, a student finds he has
leftover reagent. What should the student do?
Place the excess reagent in the appropriate solid or liquid waste container to prevent
contamination of the stock reagent.
List the correct procedure for lighting and working with a Bunsen burner.
1. Make sure all loose clothing and hair have been properly restrained and will not
contact the flame accidentally.
2. Prepare the workspace to be sure no flammable materials are in the vicinity of the
open flame
3. Inspect the tubing to the gas valve to be sure it does not have any cracks or holes
that would allow a gas to leak.
4. Inspect the burner to be sure that the air intake and fuel valves work properly and can
be adjusted.
5. With the sparker in hand, turn on the gas and light the flame as soon as possible to
minimize unburned gas in the air.
6. Adjust the fuel valve to set the height of the flame and adjust the air intake valve to
adjust the temperature (color) of the flame according to the instructions in the lab
manual.
7. Monitor the flame and all nearby materials closely until the experiment is complete.
Never leave an open flame unattended.
8. Shut off the burner and gas valve as soon as experimental work is completed, or
anytime you must leave the flame unattended.
List the basic order of steps for beginning any experimental procedures.
1. Take any personal safety precautions that are warranted.
2. Prepare your workspace.
3. Inspect your equipment to make sure it is functioning properly.
When should you inspect the glassware in your drawer for chips, cracks, or
chemical residues?
Glassware should be inspected during an experiment (before using any glassware),
before beginning an experiment, and during check-in (where any glassware can be
replaced for free) in order to prevent injuries, accidents, or unwanted complications.
, Suppose a beaker of solid reagent drops onto the bench and cracks. What is the
best way to dispose of this?
To the extent possible, solid reagent should be added to the solid waste container and
broken glass should be added to the glass waste. Hazardous materials should never be
added to glass waste, and broken glass should only be allowed in solid waste with the
TA's permission.
Why does the lab safety policy address loose clothing, dangling jewelry, and
contact lenses?
Loose clothing/dangling jewelry: can impede movement, knock materials over, can
present a fire hazard.
Contact lenses: can hold hazardous chemicals close to the eyes.
All of these items increase the risk of injury.
Your lab partner accidentally gets a mist of your solution in her eye. You
immediately help her to the eye wash to rinse it. After about a minute, she feels
better and is ready to get back to work. What should you do?
Keep her in the eye wash for at least 15 minutes, and then make sure she goes to
student health, just to be sure.
When reading the label on a reagent container, what are the three most important
pieces of information?
Name, concentration, and hazard warning(s)
What are important precautions before using a hot plate?
Remember that the ceramic top of the hot plate, and any glassware heated by the hot
plate will look the same when hot as cold, and will not cool down until well after the hot
plate has been shut off.
Never leave the hot plate turned on an unattended.
Set up your work space with the hot plate in a secure location away from the edge of
the bench so that you won't accidentally bump it and spill hot or flammable liquids.
Set up your work space so that wires and cables cannot accidentally make contact with
the ceramic surface and melt.
Set up the work space so that flammable materials - notebooks, paper towels, other
reagents, etc. - are far away from the hot plate to prevent them coming in contact with
the hot surface.
If you need to work with a flammable or volatile solvent, which piece of lab
equipment should you be sure to use?
Fume hood with good ventilation.
Your lab partner accidentally spills some acid on his wrist and watchband. What
should you do?
Let the TA inspect his wrist to see if it is okay.
Remove the watch and wristband immediately, and rinse his wrist for at least 15
minutes to be sure all hazardous material has been washed away.
For which of the following situations should you be sure to notify your TA and fill
out an incident report form?
You begin to feel faint and dizzy in lab because you had to skip lunch.
You accidentally pick up a beaker from the hot plate, not realizing that it was already
hot, and the edge of the beaker leaves a small red mark on your thumb.
During lab check-out at the end of the semester, your lab partner accidentally drops a
If a flammable substance in a beaker should catch fire while you are working but
the flames are relatively contained, what should you do to extinguish the flame?
What should you not do?
DO: Use the chemical fire extinguisher from the lab. Pull the pin, aim the nozzle to the
beaker, and pull the lever.
DO (Best, simplest): Turn off the heat source immediately and use a watch glass to
cover the beaker.
DON'T: Use water from the nearest sink to douse the flame.
How many times should you read the label on a reagent container and compare it
with the lab manual?
At least twice each time you remove material from the container.
While weighing out a reagent for use in an experiment, a student finds he has
leftover reagent. What should the student do?
Place the excess reagent in the appropriate solid or liquid waste container to prevent
contamination of the stock reagent.
List the correct procedure for lighting and working with a Bunsen burner.
1. Make sure all loose clothing and hair have been properly restrained and will not
contact the flame accidentally.
2. Prepare the workspace to be sure no flammable materials are in the vicinity of the
open flame
3. Inspect the tubing to the gas valve to be sure it does not have any cracks or holes
that would allow a gas to leak.
4. Inspect the burner to be sure that the air intake and fuel valves work properly and can
be adjusted.
5. With the sparker in hand, turn on the gas and light the flame as soon as possible to
minimize unburned gas in the air.
6. Adjust the fuel valve to set the height of the flame and adjust the air intake valve to
adjust the temperature (color) of the flame according to the instructions in the lab
manual.
7. Monitor the flame and all nearby materials closely until the experiment is complete.
Never leave an open flame unattended.
8. Shut off the burner and gas valve as soon as experimental work is completed, or
anytime you must leave the flame unattended.
List the basic order of steps for beginning any experimental procedures.
1. Take any personal safety precautions that are warranted.
2. Prepare your workspace.
3. Inspect your equipment to make sure it is functioning properly.
When should you inspect the glassware in your drawer for chips, cracks, or
chemical residues?
Glassware should be inspected during an experiment (before using any glassware),
before beginning an experiment, and during check-in (where any glassware can be
replaced for free) in order to prevent injuries, accidents, or unwanted complications.
, Suppose a beaker of solid reagent drops onto the bench and cracks. What is the
best way to dispose of this?
To the extent possible, solid reagent should be added to the solid waste container and
broken glass should be added to the glass waste. Hazardous materials should never be
added to glass waste, and broken glass should only be allowed in solid waste with the
TA's permission.
Why does the lab safety policy address loose clothing, dangling jewelry, and
contact lenses?
Loose clothing/dangling jewelry: can impede movement, knock materials over, can
present a fire hazard.
Contact lenses: can hold hazardous chemicals close to the eyes.
All of these items increase the risk of injury.
Your lab partner accidentally gets a mist of your solution in her eye. You
immediately help her to the eye wash to rinse it. After about a minute, she feels
better and is ready to get back to work. What should you do?
Keep her in the eye wash for at least 15 minutes, and then make sure she goes to
student health, just to be sure.
When reading the label on a reagent container, what are the three most important
pieces of information?
Name, concentration, and hazard warning(s)
What are important precautions before using a hot plate?
Remember that the ceramic top of the hot plate, and any glassware heated by the hot
plate will look the same when hot as cold, and will not cool down until well after the hot
plate has been shut off.
Never leave the hot plate turned on an unattended.
Set up your work space with the hot plate in a secure location away from the edge of
the bench so that you won't accidentally bump it and spill hot or flammable liquids.
Set up your work space so that wires and cables cannot accidentally make contact with
the ceramic surface and melt.
Set up the work space so that flammable materials - notebooks, paper towels, other
reagents, etc. - are far away from the hot plate to prevent them coming in contact with
the hot surface.
If you need to work with a flammable or volatile solvent, which piece of lab
equipment should you be sure to use?
Fume hood with good ventilation.
Your lab partner accidentally spills some acid on his wrist and watchband. What
should you do?
Let the TA inspect his wrist to see if it is okay.
Remove the watch and wristband immediately, and rinse his wrist for at least 15
minutes to be sure all hazardous material has been washed away.
For which of the following situations should you be sure to notify your TA and fill
out an incident report form?
You begin to feel faint and dizzy in lab because you had to skip lunch.
You accidentally pick up a beaker from the hot plate, not realizing that it was already
hot, and the edge of the beaker leaves a small red mark on your thumb.
During lab check-out at the end of the semester, your lab partner accidentally drops a
