Chem 241 Safety Quizes

What concentration of HCl or NaOH (1M or 6M) should be used in a seperatory funnel during an extraction and why?

1M instead of 6M so there is more water to dissolve water-soluble components

What sort of condenser should you use and why?

A water condenser instead of an air condenser because it is better at preventing your solvent and/or products from evaporating

Which of the following organic solvents are flammable (choose all that apply)

Acetone, Methyl tert-butyl ether, Toluene, Dimethyl carbonate, Cyclohexane

If you are unsure which layer of your separatory funnel is the organic layer and which is the aqueous layer, which of these is the safest way to figure it out? (Choose one)

Add a few drops of water to each layer to see if the water mixes in (aqueous layer) or forms a separate layer (organic)

The procedure states you should cool the reaction vial in an ice bath before adding ferrocene. Why is this necessary? (choose 1)

Because the reaction is exothermic and might spontaneously boil away the solvent

You are using sodium hypochlorite to oxidize borneol to camphor. What common household item is sodium hypochlorite found in?

Bleach

If you have excess unreacted magnesium at the end of the lab, how should you dispose of it? (choose one)

Dissolve it in 6M HCl

What are hazards of dry ice? (choose all that apply)

It can cause cryogenic burns, In sufficient quantity, it can displace oxygen and cause suffication

Bromine must be removed from glassware before you rinse that glassware out with acetone. If acetone and bromine are mixed, they will produce bromoacetone. Why is bromoacetone very unpleasant? (choose one)

It is a lachrymator because it reacts with water in your eyeball to produce HBr, making you cry and causing a lot of pain

What properties allow bromine to cause this health risk?

It is a strong oxidizing agent, It is volatile and easily inhaled

What properties allow bromine to cause this health risk? (choose all that apply)

It is a strong oxidizing agent, It is volatile and easily inhaled

Why is it important to increase the amount of solvent used if a reaction or purification procedure is scaled up? (select all that apply)

To ensure that the larger amount of material remains soluble, To help protect the solution against large temperature changes from exothermic or endothermic processes, To increase the amount of material that is transferred from 1 layer to another during an extraction

Which of the following should you do if the contents of your separatory funnel spill on yourself? (choose all that apply)

Alert your TA even if you have to shout, Rinse the affected area with plenty of water, Remove any affected clothing

How should hood sashes be positioned?

As low as possible at all times

If you don't understand part of the lab procedure, what should you do? (Choose 1)

Ask the TA for help

Why must the reaction temperature be carefully maintained at 50C instead of allowing the solution to reflux at 100C? (choose all that apply)

At 100C, there is a higher risk of unwanted side reactions, Sodium hypochlorite is unstable at higher temperatures

When must you wear safety goggles in lab? (Choose 1)

At all times, including when using computers in the instrument room

What are some of the hazards of dichloromethane (also known as methylene chloride)? (choose all that apply)

Carcinogenic, Can cause chemical burns upon skin contact, Very volatile and easy to inhale

What are some of the hazards of sodium hypochlorite? (choose all that apply)

Chemically reacts to form toxic chlorine gas, Corrosive if you spill it on your skin, Poisonous if ingested

Which of the following actions are NOT permitted in lab? (Check all that apply)

Chewing gum, Eating and drinking, Texting, Listening to an iPod with headphones on, Leaving a water bottle and bag of chips on the floor to consume outside after lab is over, Smoking (tobacco, marijuana, or electronic)

Which of the following are true about mixing liquids in a separatory funnel? (choose all that apply)

Everything should be done in your hood, You should wear gloves, Your hood sash should be between your face and the separatory funnel, Don't aim the separatory funnel at anyone, You should have a firm grip on the stopper and vent the funnel frequently by using the stopcock

If you have extra time, you can try out your own experiment

False

It's acceptable to bring a box of donuts into lab to thank your TA for their hard work and assistance.

False

Unused chemicals should be returned to their original containers to save money

False

What are the main hazard(s) of sodium methoxide in methanol and potassium tert-butoxide in tert-butanol? (choose all that apply)

Flammable, Corrosive, Methanol is toxic

Often when quenching the reaction with water, a puff of corrosive smoke is seen. What is the origin of this smoke? (choose 1)

HCl being released from the reaction

What flammable gas is produced if sodium borohydride is mixed with water? (choose 1)

Hydrogen

How should broken glassware and used glass pipettes be disposed of? (Choose one)

In designated laboratory glass boxes

If you spill bromine on the bench, what actions should you take?

Inform your TA of the spill, Quench the bromine with sodium bisulfite (a reducing agent)

If you spill bromine on the bench, what actions should you take? (choose all that apply)

Inform your TA of the spill, Quench the bromine with sodium bisulfite (a reducing agent)

What is the main health risk of liquid bromine? (choose one)

It is corrosive and causes chemical burns

What action(s) should you take to reduce the health risk of silica gel? (choose all that apply)

Keep it wet with solvent so less powder gets into the air, Handle the silica gel in the fume hood, If some silica gel spills, wipe it up with a wet paper towel, not a dry paper towel, Wear personal protective equipment such as gloves and a lab coat to avoid getting silica gel on yourself

When can diethyl ether and bunsen burnes be used together in lab?

No ether is allowed in lab until after everyone is finished with bunsen burners

Which of the following activities in this experiment can be performed outside the fume hood? (choose all that apply)

None of the above since they must all be carried out in the fume hood

If some of the bromine/hydrobromic acid mixture spills on you, what actions should you take? (choose all that apply)

Remove your gloves and/or lab coat if any spilled, Wash any affected skin with plenty of water, If it got in your eyes, rinse them at the eye wash for 15 minutes, Alert your TA

If some of the bromine/methylene chloride mixture spills on you, what actions should you take?

Remove your gloves and/or lab coat if any spilled, Wash any affected skin with plenty of water, If it got in your eyes, rinse them at the eye wash for 15 minutes, Alert your TA

What clothing is NOT allowed to be worn in lab? (Choose all that apply)

Sandals and other open toed shoes, Shorts

Which of the following materials should you place into solid chemical waste containers? (Choose all that apply)

Solid chemicals you took too much of, Chemicals used for drying your product

Whenever you heat liquids, especially near their boiling point, you should always use a stir bar or boiling stones. Why is this? (Choose one)

Stirring prevents the liquid from bumping out of the flask

Why should the crystallization solvents be heated in a water bath rather than directly on the hot plate? (choose all that apply)

The hot plate would get too hot and might boil away the solvent, The hot plate would get too hot and be a fire risk with the flammable organic solvent

What is the definition of "flash point"? (choose one)

The lowest temperature at which a liquid can vaporize to form an ignitable mixture in the air

When assembling a simple or fractional distillation apparatus, where should clamps be placed?

The piece of glassware closest to the ground (the round bottom flask) should be clamped along with other glassware that's not directly above the round bottom flask such as the condenser

Why should your disposal of excess magnesium take place in a fume hood? (choose all that apply)

The quench released hydrogen gas, which is flammable and explosive, The quench is highly exothermic and might cause the solvent to splash, HCl is corrosive

Which of the following is correct about the order of adding solvent to your round bottom flask? (choose one)

The solvent should be added to your flask before you begin heating to ensure that the solvent doesn't ignite on the hot thermowell surface

What is the main hazard present when using the GC? (choose 1

Thermal burns from the hot injector port and oven

Why must all parts of the oxidation and reduction reactions be carried out in the fume hood? (choose all that apply)

To protect you against any unplanned explosions, To isolate any toxic gases produced, In case any reactions accidentally ignite

Assume all chemicals in lab are dangerous

True

Don't leave lit Bunsen burners unattended

True

Hot glassware and hot hotplates look the same as cold glassware and cold hotplates.

True

Long hair needs to be tied back, regardless of gender

True

You must read the procedure before entering the lab

True

Your fume hood and all communal work spaces should be kept clean and tidy

True

Which of the following statements about waste disposal are correct? (Choose all that apply)

Water from the water bath can go down the drain, Solid chemicals should go in solid waste bins while filter paper and weighing paper go in the trash, The mother liquor from your crystallization solutions goes in the organic waste

Silica gel is not flammable, nor is it chemically reactive. Why then is it considered hazardous, particularly with long term exposure? (choose 1)

When inhaled it damages the respiratory tract

When are you allowed to enter the lab? (Choose all that apply)

When it is the official lab start time and your TA has arrived, When you are wearing goggles and a lab coat

When must you wear gloves in lab? (choose 1)

When you are performing an experiment that involves hazardous materials