Basic Laboratory Techniques - MeitY OLabs
Summary
TLDRThis video covers basic laboratory techniques using a Bunsen burner. It explains how to produce luminous and non-luminous flames, bend and cut glass tubes, and draw glass jets. The tutorial also demonstrates the creation of a wash bottle and the process of boring a cork, including softening it in water and fitting glass tubes into the bore. Each step is clearly outlined, providing a practical guide for students or professionals working in a laboratory setting.
Takeaways
- đ„ A Bunsen burner is used for producing a non-luminous flame by opening the air hole, and a luminous flame by closing it.
- ⥠A spark lighter is required to ignite the Bunsen burner once the gas is turned on.
- đ§Ș When bending a glass tube, it must be heated in a non-luminous flame until soft and then gently pressed onto a tile to make it coplanar.
- đȘ A glass tube can be cut by making a deep scratch with a triangular file, then using pressure to snap it cleanly along the scratch.
- 𧏠To draw a glass jet, the tube is heated, softened, and stretched until the middle portion is thin, then cut with a file.
- đ§ A wash bottle can be created using a 500ml flask and corks with bores, allowing for controlled streams of water through angled tubes.
- đ ïž Corks are softened by dipping them in water and pressing them, making them easier to bore for fitting tubes.
- đ When fitting a glass tube into a bored cork, wet the tube end with water and rotate it into the cork for a smooth fit.
- đŻ To bore a cork, mark the spot, twist a borer into the cork while applying downward force, creating a clean hole from end to end.
- đ The ends of glass jets can be rounded by heating them gently in a flame for a short period, ensuring smooth edges.
Q & A
What is the purpose of the Bunsen burner in the described experiments?
-The Bunsen burner is used to produce a flame that can be adjusted to either a luminous or non-luminous state for various laboratory tasks, such as bending or cutting glass tubes.
How can you produce a luminous flame with a Bunsen burner?
-A luminous flame is produced by closing the air hole of the Bunsen burner using the air adjusting disc.
What is the process of bending a glass tube?
-To bend a glass tube, heat it over the non-luminous flame while rotating it until it softens. Then apply gentle pressure so that the tube bends by itself, place it on a glazed tile, and press it gently to make it coplanar before allowing it to cool.
What materials are required for bending a glass tube?
-The materials required are a Bunsen burner, a glass tube, and a glazed tile.
How do you safely cut a glass tube?
-To cut a glass tube, scratch it deeply with a triangular file, then place your thumbs on each side of the scratch and apply pressure with a quick bending motion until it breaks smoothly.
What is the process of drawing a glass jet?
-To draw a glass jet, heat a glass tube in a flame until it softens, then gently pull the two ends in opposite directions to thin the middle section. Once cooled, scratch the narrow part with a triangular file and snap it with a quick bending motion.
What is the purpose of a wash bottle in the laboratory, and how is it made?
-A wash bottle is used to produce a stream of water. It is made by filling a 500ml flat-bottom flask with distilled water, inserting two bent tubes through a cork, and blowing air through the tubes to release the water.
How do you soften a cork for boring?
-To soften a cork, dip it in water, wrap it in filter paper, and then press it in a cork-presser until it becomes flexible.
What are the steps to bore a hole in a cork?
-First, mark the position of the hole on the cork, then place a borer on the mark, apply downward force while twisting it, and bore the cork from one end to the other.
How do you insert a glass tube into a bored cork?
-Wet the end of the glass tube, dip the bored cork in water, and insert the tube by rotating it gently to fit the tube securely into the hole.
Outlines
đ„ Basic Laboratory Techniques: Lighting a Bunsen Burner
This section introduces basic laboratory procedures involving a Bunsen burner. It explains the steps to light a Bunsen burner using a spark lighter, adjust the air hole to control flame type (luminous vs. non-luminous), and the significance of these flame types for various experiments.
đ§ Bending a Glass Tube
The paragraph explains how to bend a glass tube safely. It involves using a Bunsen burner to soften the glass by holding it in the non-luminous flame, applying gentle pressure to bend the tube, and ensuring it becomes coplanar by pressing it onto a glazed tile. Finally, the glass is allowed to cool, completing the bending process.
âïž Cutting a Glass Tube
This section describes the method of cutting a glass tube. It involves placing the glass tube on a surface, making a deep scratch using a triangular file, and applying a quick bending motion at the scratch point to break the tube cleanly into two parts.
đŹ Drawing a Glass Jet
In this part, the process of drawing a glass jet is detailed. A glass tube is softened over a Bunsen burner, pulled apart to a thin diameter, scratched with a triangular file, and broken into two jets. The ends of the jets are rounded by heating them in the flame.
đ§ Assembling a Wash Bottle
The paragraph describes assembling a wash bottle using a 500ml flask filled with distilled water and a cork with two angled bores. One tube at a 60-degree angle and another at a 120-degree angle are inserted. When air is blown into the 120-degree tube, water streams out from the other tube. When the flask is tilted, more water is dispensed through the tubes.
𧎠Softening and Boring a Cork
This section explains how to soften and bore a cork. The cork is softened by soaking it in water, then pressed in a cork-presser. Afterward, a hole is bored by marking the positions with a pencil, placing the borer on the mark, and twisting it while applying pressure to create a clean hole through the cork.
đ§Ș Fitting a Glass Tube into a Bored Cork
The final paragraph outlines the process of inserting a glass tube into a bored cork. The bored cork is dipped in water, and the end of the glass tube is wetted before being rotated into the corkâs hole, completing the fitting process.
Mindmap
Keywords
đĄBunsen burner
đĄNon-luminous flame
đĄLuminous flame
đĄGlass tube
đĄAir adjusting disc
đĄTriangular file
đĄCork
đĄWash bottle
đĄSoftening glass
đĄBoring a cork
Highlights
A Bunsen burner is required for producing both luminous and non-luminous flames.
A spark lighter is used to ignite the Bunsen burner.
Closing the air hole of the Bunsen burner produces a luminous flame.
Opening the air hole of the Bunsen burner produces a non-luminous flame.
Glass tubes can be bent by heating them in a non-luminous flame until soft, then applying gentle pressure.
After bending, the glass tube is placed on a glazed tile to ensure it becomes coplanar.
Glass tubes can be cut by making a deep scratch with a triangular file and applying pressure on both sides.
Two glass tubes can be obtained from a single tube by cutting it smoothly at the scratch.
To draw a glass jet, heat a glass tube in a flame until it softens, then pull the ends in opposite directions.
After drawing out the middle portion to a thickness of 2mm, the tube can be cooled and cut to form glass jets.
A wash bottle is created by fitting two angled tubes into the bores of a cork and blowing air through them.
The stream of water in a wash bottle is controlled by the angle at which the flask is tilted.
Corks are softened by soaking them in water and pressing them in a cork-presser.
A cork borer is used to make holes in corks by twisting it and applying downward force.
Glass tubes can be fitted into the bored corks by wetting the end of the tube and rotating it into the hole.
Transcripts
Basic laboratory techniques
Bunsen burner
We require, a Bunsen burner and a spark lighter.
Take a spark lighter.
Turn the gas on and light the burner.
A non - luminous flame is produced.
On closing the air hole of the burner by rotating the air adjusting disc, a luminous flame is
produced.
On opening the air hole of the burner, a non - luminous flame is produced.
Bending a glass tube
We require, Bunsen burner, glass tube and glazed tile.
Take a glass tube.
Hold the glass tubing between the thumb and fingers.
Introduce it lengthwise into the non-luminous flame of the burner.
Keep the tube rotating till it softens.
Apply gentle pressure so that it bends by itself.
Remove the tubing from the flame.
Place the bent limb on the glazed tile and press it gently so as to makes it coplanar.
Allow the tubing to cool.
Cutting a glass tube
Take a glass tube.
Place it on the table.
Hold it firmly and make a single deep scratch with a triangular file.
Place the thumbs on each side of the scratch at equal distances from it and with a pressure
give a quick bending motion until it breaks smoothly.
Thus we got two tubes from a single tube.
Drawing a glass jet
We require, Bunsen burner, a glass tube of required length and triangular file.
Take a glass tube of required length.
Hold it with both hands.
Place it lengthwise in flame.
Keep rotating the tube till it softens.
Take the tubing out of the flame and gently pull the two ends in the opposite directions.
The middle portion is drawn out to a thickness of about 2mm.
Allow the tubing to cool.
Hold it firmly and make a single deep scratch on the narrow portion with a triangular file.
Place the thumbs on each side of the scratch at equal distances from it and with a gentle
pressure give a quick bending motion until it breaks smoothly.
Finally round the ends of the jets by heating in the flame for a short time.
Thus, we got two glass jets from a delivery tube.
Wash bottle
Fill a flat bottom flask of 500ml with distilled water.
An appropriate cork with two bores is fitted into it.
One tube which bends at an angle of 60 degree is passed through one of the bore in the cork.
Then pass another tube which bends at an angle of 120 degree through other bore in the cork.
On blowing out air through the tube which bends at an angle of 120 degree, a stream
of water comes out from the other tube.
On tilting the flask and blowing out air through the tube which bends at an angle of 60 degree,
a little larger amount of water comes out from the other tube.
Boring a cork
Softening of the cork
Take a cork and dip it in water until it becomes flexible.
Take the cork from water.
Wrap the cork in a filter paper.
Place the wetted cork in a cork - presser and press it to soften it.
Thus, cork is softened.
Boring of the cork
Place the cork on the table with its narrow end upward.
Mark the position of the hole on both the sides of the cork with a pencil.
Take a borer and place it on the mark on the cork.
Apply force downwards on the borer and twist it at the same time.
The cork is bored from one end to the other.
Fitting a glass tube in the bore Dip the bored cork in water.
Take a glass tube and wet the end of the tube with water.
Insert the tube into the bore by rotating it.
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