Chemical Safety and Storage Practices

Questions and Answers

What should be done with items contaminated with hazardous materials before removal from the hood?

They can be removed without any precautions.

They should be left in the hood indefinitely.

They should be decontaminated or placed in a closed container. (correct)

They should be destroyed immediately.

Which chemical should not be stored with ammonia solution?

Acetic acid solution. (correct)

Cyclohexane solution.

2-Propanol solution.

Sodium hydroxide solution.

What is the primary consideration when storing chemicals?

Frequency of usage

Cost of the chemicals

Compatibility with other chemicals (correct)

Size of the container

Which of the following chemicals is classified as an oxidizer?

Potassium dichromate Signup and view all the answers

What should be avoided while operating a UV-Vis spectrophotometer?

Keeping the sample compartment open during use. Signup and view all the answers

Which of the following equipment does NOT require annual third-party calibration?

Sets of weights Signup and view all the answers

In starting up laboratory operations, which should be done first?

Turning on the hoods, vents, and exhaust fans. Signup and view all the answers

What action should be taken before turning on the UV-Vis spectrophotometer?

Check if the sample holder is empty. Signup and view all the answers

What pH level qualifies waste as ‘alkali waste’?

pH > 12.5 Signup and view all the answers

Which of these describes a person who produces hazardous wastes?

Waste generator Signup and view all the answers

Which hazardous waste characteristic applies to aqueous solutions with a pH less than or equal to 2 or greater than or equal to 12.5?

Corrosivity Signup and view all the answers

What defines ignitability in hazardous waste?

Flash point less than 140°F Signup and view all the answers

What best describes residual wastes?

Material that can no longer be beneficially reused Signup and view all the answers

Which waste materials are classified as hazardous due to their ability to puncture skin?

Hazardous glass and plastics Signup and view all the answers

What is the definition of reactivity in the context of hazardous waste?

Generation of toxic fumes upon interaction with water Signup and view all the answers

What characteristic of hazardous waste applies to any material that is unstable or has explosive potential?

Reactivity Signup and view all the answers

Which hazardous waste characteristic indicates the potential to contaminate groundwater if improperly disposed of?

Toxicity Signup and view all the answers

What is the term for organic chemicals that resist environmental degradation?

Persistent Organic Chemicals (POPs) Signup and view all the answers

Which method is recognized as a solid waste management practice that breaks down organic matter?

Composting Signup and view all the answers

What is the term used for liquid that has extracted dissolved and suspended matter from a landfill?

Leachate Signup and view all the answers

What practice should be avoided when handling liquid chemicals?

Carrying acid in an open container Signup and view all the answers

Which of the following describes a characteristic of waste that is able to ignite easily?

Ignitability Signup and view all the answers

Which term refers to the process of cleaning up contaminated environments using biological methods?

Bioremediation Signup and view all the answers

Which hazardous characteristic does NOT imply a material's ability to corrode?

Dermatitis potential Signup and view all the answers

What is the correct method for using a pipette marked with 'To Deliver' (TD)?

Allow a small amount of liquid to remain in the tip. Signup and view all the answers

Which statement about cuvette cleaning is true?

Cuvettes should be cleaned in an ultrasonic cleaning bath. Signup and view all the answers

What must be true about opposing tubes when operating a centrifuge?

They must be of equal weight. Signup and view all the answers

What should be avoided to ensure thorough cleaning of glassware?

Leaving a uniform film of water on glassware. Signup and view all the answers

What is the expected concentration of potassium dichromate in Solution 2 expressed in two significant figures?

3.1 mol/L Signup and view all the answers

Which statement about Class B volumetric glassware is correct?

It does not meet ASTM standards. Signup and view all the answers

What is the titration reaction equation for sodium hydroxide and hydrochloric acid?

NaOH(aq) + HCl(aq) ↔ NaCl(aq) + H2O(l) Signup and view all the answers

When reading the volume on a burette, at what position should your eye be in relation to the liquid level?

Higher than the liquid level. Signup and view all the answers

What laboratory glassware is appropriately used to measure 25.0 mL of sodium hydroxide?

Pipette Signup and view all the answers

How should dilutions with volumetric flasks be performed for accuracy?

Dilute to the mark with distilled water. Signup and view all the answers

What is a common misconception regarding the cleaning of laboratory glassware?

All glassware can be cleaned the same way. Signup and view all the answers

In Solution 5, what is the concentration of potassium dichromate expressed in two significant figures?

1.2 x 10^-2 mol/L Signup and view all the answers

Which statement is true regarding the disposal of broken laboratory glassware?

It should be collected in designated sharps containers. Signup and view all the answers

What is the correct approach to storing concentrated acids and bases?

They should be stored separately in corrosion-resistant materials. Signup and view all the answers

What is the concentration of potassium dichromate in Solution 3, expressed in two significant figures?

0.61 mol/L Signup and view all the answers

Which statement regarding fire extinguishers in laboratories is false?

Fire extinguishers can be stored under chemical fume hoods. Signup and view all the answers

Study Notes

Chemical Storage and Safety

Storage cabinets should be used for corrosives, oxidizers, carcinogens, and respiratory sensitizers.
Contaminated items must be decontaminated or placed in closed outer containers before removal from hoods.

Ammonia Solution Compatibility

Ammonia solution cannot be stored with acetic acid, sodium hydroxide, 2-propanol, or cyclohexane.

Chemical Storage Considerations

Prioritize storage based on the frequency of usage, compatibility, container size, and alphabetical order.

UV-Vis Spectrophotometer Operation

Check sample holder is empty before powering up, avoid keeping the sample compartment open during specific pH operations.

Waste Classification

Waste is considered “alkali” if pH is above 12.5.
Waste generation is defined by activities producing hazardous materials.

Hazardous Waste Characteristics

Ignitability applies to waste with flash points below 140°F.
Corrosivity is relevant for aqueous solutions with pH ≤ 2 or ≥ 12.5.
Reactivity is for materials that are unstable or explosive when mixed with water.

Solid Waste Management Practices

Composting aids in controlled decomposition; recycling and reducing waste are key practices.

Dilution and Concentration Calculations

Understanding volumes and concentrations is essential for proper chemical preparation and analysis.

True or False Statements

Concentrated acids and bases should be stored in corrosion-resistant materials.
Fire extinguishers must be accessible near chemical storage areas, contrary to safety practices.

Glassware and Measurement Techniques

Pipettes and burettes are fundamental for accurate measurements in titration processes.

General Laboratory Safety Guidelines

Always handle liquid chemicals carefully and protect against splashes with appropriate gear.
Never dispose of hazardous waste or broken glassware in regular trash; follow proper disposal protocols.

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Description

Test your knowledge on effective chemical storage and safety practices. This quiz covers essential topics such as compatibility of chemicals, handling hazardous waste, and operating UV-Vis spectrophotometers safely. Ensure you are well-versed in proper procedures to minimize risks in the lab.