Basic Laboratory Techniques - MeitY OLabs

amritacreate

8 Feb 201705:27

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

🔥 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.
🧪 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.
🔪 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.
🧬 To draw a glass jet, the tube is heated, softened, and stretched until the middle portion is thin, then cut with a file.
💧 A wash bottle can be created using a 500ml flask and corks with bores, allowing for controlled streams of water through angled tubes.
🛠️ Corks are softened by dipping them in water and pressing them, making them easier to bore for fitting tubes.
🌀 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.
🎯 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.
🛁 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

00:00

🔥 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.

05:05

🔧 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.

✂️ 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.

🔬 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.

💧 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.

🧴 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.

🧪 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 cork’s hole, completing the fitting process.

Mindmap

Keywords

💡Bunsen burner

A Bunsen burner is a common piece of laboratory equipment that produces a flame for heating, sterilization, and combustion. In the video, it is used for producing both luminous and non-luminous flames, which are crucial for performing tasks such as bending and heating glass tubes.

💡Non-luminous flame

A non-luminous flame is a blue flame produced when the air hole of the Bunsen burner is open, allowing complete combustion. This type of flame is ideal for tasks that require steady heat, like bending a glass tube, as it provides a cleaner and hotter flame than a luminous flame.

💡Luminous flame

A luminous flame is a yellow, brighter flame produced when the air hole of the Bunsen burner is closed, leading to incomplete combustion. It is used for certain types of experiments but is less hot and efficient compared to the non-luminous flame.

💡Glass tube

A glass tube is a hollow cylindrical piece of glass used in laboratories for various purposes. In the video, glass tubes are heated, bent, and cut for specific tasks, such as creating jets or fitting them into corks.

💡Air adjusting disc

The air adjusting disc is a component of the Bunsen burner that controls the air supply by opening or closing the air hole. This disc is manipulated to switch between luminous and non-luminous flames during experiments like bending or heating glass.

💡Triangular file

A triangular file is a tool used for making deep scratches on glass tubes to facilitate cutting. The video demonstrates its usage in tasks like cutting glass tubes or drawing glass jets, where precise scratches are made to ensure smooth breaks.

💡Cork

A cork is a stopper used in laboratory glassware to close flasks and test tubes. In the video, corks are softened, bored, and fitted with glass tubes to create wash bottles, demonstrating how corks are modified to fit specific laboratory setups.

💡Wash bottle

A wash bottle is a laboratory apparatus used to rinse various pieces of glassware. In the video, it is constructed using a flat-bottom flask, cork, and bent glass tubes, which allow the controlled release of water when air is blown into the bottle.

💡Softening glass

Softening glass refers to the process of heating glass tubing over a flame until it becomes malleable enough to bend or shape. The video shows how glass is softened in a non-luminous flame to create bends and form specific shapes like jets.

💡Boring a cork

Boring a cork involves creating holes in the cork to insert glass tubes. This technique is shown in the video, where a cork is softened and then bored with a tool to accommodate glass tubes for various laboratory setups, such as wash bottles.

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.