Safety Quizzes

What concentration of HCl or NaOH should be used in separatory funnel during an extraction and why?

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

What sort of condenser do 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?

Acetone MTBE Toluene Dimethyl carbonate Cyclohexane

If you are unsure which layer of the separatory funnel is the organic layer and which is the aqueous layer, which of these is the safest way to figure out?

Add a few drops of water to each layer to see if the water mixes (aqueous) 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?

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

What color is the tip of the sealed NMR tube that contains the standby reference solvent?

Blue

Why must deuterated solvents be used to prepare NMR samples?

Deuterated solvents are "invisible" in an 1H NMR spectrum while non-deuterated solvents will obscure important peaks

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

Dissolve it in 6M HCl

Bromine must be removed from glassware before rinsing with acetone. Why is bromoacetone unpleasant?

It is a lacrymator because it reacts with water in your eye 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

What are the hazards of dry ice?

Cryogenic burns It can displace oxygen and cause suffocation

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

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

Why is it important to increase the amount of solvent used if a reaction or purification procedure is scaled up?

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?

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?

Ask the TA for help

When must you wear safety goggles in lab?

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

What are some of the hazards of dichloromethane?

Carcinogenic, chemical burns, volatile

Which of the following actions are not permitted in lab?

Chewing gum Eating and drinking Texting Listening to an ipod Leaving a water bottle on floor Smoking

Which of the following are true about mixing liquids in a separatory funnel?

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 doughnuts 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 hazards of sodium methoxide in methanol and potassium tert-butoxide in tert-butanol?

Flammable, corrosive, methanol is toxic

When and why should you wear gloves when preparing NMR samples and acquiring NMR data?

Gloves should be worn while preparing the NMR sample because you are handling hazardous solvents, but gloves should not be warn while using the NMR spectrometer to avoid contaminating the computer keyboard, and should not be worn in the hallway

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

HCl being released from the reaction

What flammable gas is produced if sodium borohydride is mixed with water?

Hydrogen

How should broken glassware and used glass pipettes be disposed of?

In designated laboratory glass boxes

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

Inform TA Quench the bromine with sodium bisulfite

How and when should you put the machine into standby mode?

Insert the sealed-glass standard tube and click standby on the attached PC right after you email yourself your NMR file, even if other students are waiting

What is the main health risk of liquid bromine?

It is corrosive and causes chemical burns

What actions should you take to reduce the health risk of silica gel?

Keep it wet with solvent Handle in fume hood Wipe with wet paper towel, not dry Wear personal protective equipment

When can diethyl ether and bunsen burners 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?

None of the above

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

Remove gloves Wash affected skin with water Rinse eye for 15 minutes Alert TA

What clothing is not allowed to be worn in lab?

Sandals Shorts

Which of the following materials should you place into solid chemical waste containers?

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?

Stirring prevents the liquid from bumping out of the flask

What happens if you choose the wrong solvent while setting up your NMR experiment?

The NMR spectrometer will acquire data for the wrong chemical shift range and you will likely not have any usable data when you open spinworks

Why should the crystallization solvents be heated in a water bath rather than directly on the hot plate?

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?

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 should be clamped along with other glassware that's not directly above the round bottom flask such as the condenser

Why should you dispose of excess magnesium in fume hood?

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

What is the main hazard present when using GC?

Thermal burns from the hot injector port and oven

Why must all parts of the reduction reaction be carried out in the fume hood?

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

Assume all chemicals in the 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 about waste disposal are correct?

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 is it considered hazardous?

When inhaled it damages the respiratory tract

When are you allowed to enter the lab?

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?

When you are performing an experiment that involves hazardous materials