Table of Contents
- 1 Which of the following should not be close to flammable materials?
- 2 Why should you never heat heavy walled glassware directly with a flame?
- 3 What substances are flammable?
- 4 What are examples of flammable liquids?
- 5 What materials should not be placed directly on the balance pan?
- 6 What precaution can you take against chemical contamination in reagent bottles?
- 7 Which is part of the flame burns no carbon?
- 8 Is there a flame that does not produce soot?
Which of the following should not be close to flammable materials?
Lab Safety
| Question | Answer |
|---|---|
| Which of the following should not be close to flammable materials? | a lighted burner |
| A student’s hand is cut during a laboratory. What should the student do immediately? | tell the teacher |
| What should students do before inserting the plug of an electrical device into a socket? | make sure the area is dry |
Why should you never heat heavy walled glassware directly with a flame?
Pyrex glassware is usually safe to heat but never apply the direct heat of a flame to heavy glassware such as volumetric flasks, burettes, graduated cylinders, bottles, and thermometers. These objects break spectacularly when heated too much. Avoid heating any object too quickly.
Why are chemicals and hot objects never placed directly on the balance pan?
What do you think might be the common cause of fires in lab drawers or lockers? Chemicals and hot objects may damage a balance pan. Why are chemicals and hot objects never placed directly on the balance pan? All lab equipment should be clean, dry and cooled at the end of an experiment.
Can you heat the contents of test tubes in a flame while seated?
The open end or mouth of a test tube should never be pointed toward you or anyone else. It is safest to heat the contents of test tubes in a flame while seated.
What substances are flammable?
Flammable liquids include petrol, ethanol, methylated spirit, paint thinners, kerosene, acetone and diesel. Flammable substances includes both full and empty gas cylinders.
What are examples of flammable liquids?
Flammable: A liquid with a flash point under 100°F is considered flammable. Examples: gasoline, acetone, toluene, diethyl ether, alcohols.
What type of glassware can not heated and why?
Lead glass It cannot withstand high temperatures or sudden changes in temperature. Because lead glass is refractive and more expensive than soda-lime glass, it used to be commonly used for decorative glass dishware.
What types of glassware may be heated?
What type of glassware can be heated in a science lab?
- Florence: Also known as Boiling Flask is lab equipment that is ideal for operations that involve heating.
- Erlenmeyer Flask: Erlenmeyer Flask is commonly known as conical flasks too.
- Sidearm flask: The sidearm flask also goes by the name Buchner.
What materials should not be placed directly on the balance pan?
Only glass, ceramic, metal or plastic objects and containers should be placed in direct contact with the balance pan. Do not handle objects to be weighed with bare hands. Moisture, grease and dirt on you fingers will affect the weight of the objects. To be weighed accurately, all objects must be at room temperature.
What precaution can you take against chemical contamination in reagent bottles?
To avoid contamination of the chemical reagents, never insert droppers, pipets, or spatulas into reagent bottles. Do not return chemicals to the original containers – To avoid contamination of chemicals, dispose of used chemicals according to your instructor’s instructions.
When you heat a substance in a test tube where should it point?
21. When heating a substance: – When heating a substance in a test tube, always point the open end of the container away from yourself and others. – Never leave anything that is being heated or is visibly reacting unattended.
What precaution should be considered when a test tube has been heated or being heated?
1 Answer
- Always wear safety glasses.
- Always point the test tube away from any other person in the lab.
- Heat the test tube being held at an angle so there is a way for the gases produced to escape safely.
- Heat the test tube at the top of the solution not the bottom where a gas bubble can cause an explosion.
Which is part of the flame burns no carbon?
The flame is therefore non-luminous. The flame has three district zones each with a different colour. Cool inner zone – this is a zone of unburnt gas. Green/blue zone – part of the gas burns in this zone because there is not enough air to burn all the gas completely. However, no carbon is formed.
Is there a flame that does not produce soot?
The temperature can be adjusted easily to produce a non-luminous flame, which does not produce much soot. The spirit burner can also produce a soot-free flame. But the flame is not hot enough to effect (produce) some chemical reactions. Apart from that, the burner is filled with spirit, a substance that is highly flammable.
Can a solid or liquid burn with a flame?
For any solid or liquid to burn with a flame, it must first turn into inflammable vapours (gaseous state). A flame can be luminous or non-luminous. Flames of a candle and any oil are usually smoky and luminous. Flames of such kind are normally of little laboratory use.
Which is the best heat source for chemistry?
Name different heat sources which can be used in a chemistry laboratory The Bunsen burner is the best of all burners because it is convenient to handle. Another advantage of the Bunsen burner is that it produces a hot flame whose temperature is approximately 1000°C.