Lab Safety & Experiment 1 Study Guide
Question 1
At what point during the lab period should you put on goggles?
• before you walk into the lab
• right before you obtain chemicals
• goggles are only necessary to put on when working with strong acids and bases
• as soon as you open your drawer
Question 2
Indicate the order in which you should do things when finishing an experiment.
• Dispose of any waste (chemical or glass). → Step 1
• Wash glassware and gloves. → Step 2
• Return clean glassware and equipment to your drawer or lab shelves. → Step 3
• Put goggles, lab apron, and clean gloves in your drawer and lock it. → Step 4
Question 3
How long should you rinse off your eye in the unlikely event that you should splash some acid in it?
• For a minimum of 5 minutes.
• Until the burning sensation goes away.
• For a minimum of 15 minutes.
• Rinsing is not necessary if sodium bicarbonate is applied to neutralize it first.
Question 4
When disposing liquid organic waste, what is true? (More than one answer may be correct)
• Liquid organic waste can be discarded in the sink with plenty of running water.
• Excess organic solvents are considered liquid organic waste.
• Both solid and liquid organic waste are put in the same container.
• Liquid organic waste containers can be filled up to the brim.
• Liquid organic waste should be placed into the appropriately-marked liquid waste
container.
,Question 5
Experiment 1 – Rank the following solvents from LEAST to MOST polar
•
Question 6
Experiment 1 – Which statements should be considered when selecting a solvent for
recrystallization? (More than one answer may be correct)
• The solute should be insoluble at low temperatures.
• The solvent should have a high boiling point.
• The solvent should have a low boiling point.
• The solute should be insoluble at high temperatures.
Question 7
Experiment 1 – At which temperature would aspirin be the least soluble in water?
• 0 °C
• 15 °C
• 73 ºC
• 89 ºC
, QUIZ 2
Question 1
A student weighed out 1.423 grams of an impure solid that was supposed to be 94.1 % of the pure
product. After purifying through recrystallization and filtration, there were 0.578 grams of the pure
product. What is the percent recovery for the pure product?
Answer: 43.2%
Question 2
What is the main reason why the filter paper be dampened prior to vacuum filtration of the
filtrate?
• Damp filter paper stretches across the Büchner funnel better.
• It is important to have as much excess solvent around as possible so that the impurities stay
dissolved.
• It ensures a better seal on the funnel so that the filtrate must pass through the paper.
• It is important because it is how to check that the vacuum suction is working before adding the
filtrate to the funnel.
Question 3
After the first filtration (in Part 2), what is expected to be in the filtrate? Select all that are correct.
• aspirin
• food dye
• sucrose
• ethanol
• water
Question 4
The boiling point
for hexane is 69 ºC,
but is 77 °C for
ethyl acetate. Select
which answer(s)
explain the
difference in these
values.
Question 1
At what point during the lab period should you put on goggles?
• before you walk into the lab
• right before you obtain chemicals
• goggles are only necessary to put on when working with strong acids and bases
• as soon as you open your drawer
Question 2
Indicate the order in which you should do things when finishing an experiment.
• Dispose of any waste (chemical or glass). → Step 1
• Wash glassware and gloves. → Step 2
• Return clean glassware and equipment to your drawer or lab shelves. → Step 3
• Put goggles, lab apron, and clean gloves in your drawer and lock it. → Step 4
Question 3
How long should you rinse off your eye in the unlikely event that you should splash some acid in it?
• For a minimum of 5 minutes.
• Until the burning sensation goes away.
• For a minimum of 15 minutes.
• Rinsing is not necessary if sodium bicarbonate is applied to neutralize it first.
Question 4
When disposing liquid organic waste, what is true? (More than one answer may be correct)
• Liquid organic waste can be discarded in the sink with plenty of running water.
• Excess organic solvents are considered liquid organic waste.
• Both solid and liquid organic waste are put in the same container.
• Liquid organic waste containers can be filled up to the brim.
• Liquid organic waste should be placed into the appropriately-marked liquid waste
container.
,Question 5
Experiment 1 – Rank the following solvents from LEAST to MOST polar
•
Question 6
Experiment 1 – Which statements should be considered when selecting a solvent for
recrystallization? (More than one answer may be correct)
• The solute should be insoluble at low temperatures.
• The solvent should have a high boiling point.
• The solvent should have a low boiling point.
• The solute should be insoluble at high temperatures.
Question 7
Experiment 1 – At which temperature would aspirin be the least soluble in water?
• 0 °C
• 15 °C
• 73 ºC
• 89 ºC
, QUIZ 2
Question 1
A student weighed out 1.423 grams of an impure solid that was supposed to be 94.1 % of the pure
product. After purifying through recrystallization and filtration, there were 0.578 grams of the pure
product. What is the percent recovery for the pure product?
Answer: 43.2%
Question 2
What is the main reason why the filter paper be dampened prior to vacuum filtration of the
filtrate?
• Damp filter paper stretches across the Büchner funnel better.
• It is important to have as much excess solvent around as possible so that the impurities stay
dissolved.
• It ensures a better seal on the funnel so that the filtrate must pass through the paper.
• It is important because it is how to check that the vacuum suction is working before adding the
filtrate to the funnel.
Question 3
After the first filtration (in Part 2), what is expected to be in the filtrate? Select all that are correct.
• aspirin
• food dye
• sucrose
• ethanol
• water
Question 4
The boiling point
for hexane is 69 ºC,
but is 77 °C for
ethyl acetate. Select
which answer(s)
explain the
difference in these
values.
