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Flaming the mouth of a test tube creates an air flow. Hot air rises. Therefore dust/particles in the air are less likely to fall into your tube.
There is some controversy as to the value of this action. The hot air will also create eddy currents across the mouth of the tube or flask which may actually increase the opportunity for contamination. If there is some data which supports either view, I would like to see it. In my opinion, the reason behind flaming the mouth of a test tube has not been proven, it is just taken to be dogma.
Flaming the mouth of a test tube is done to ensure that the equipment is sterile and to prevent contaminants from entering the tube. This is important for experiments where sterility is required and to avoid any interference with the results.
The purpose of flaming the test tube when putting in or out microbes is to prevent
contamination of its content which could normally comes from the ambient air.
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What happened when you place a lighted match near the mouth of the test tube?
It depends on what is inside the test tube. If the test tube is empty nothing will happen, if there is petrol in the test tube the petrol will ignite.
In heating chemicals in a test tube where should the mouth of the test tube point?
The mouth of the test tube should be pointed away from yourself and others to prevent any splashes or fumes from coming into contact. This is important for safety measures and to avoid any potential accidents during the heating process.
Why should you never shake a test tube containing reagents by covering its mouth with a finger?
You should never shake a test tube containing reagents by covering its mouth with a finger because doing so can create pressure buildup within the test tube. This pressure can cause the test tube to explode, leading to potential injury from flying glass shards and exposure to hazardous chemicals. It is safer to use a stopper or cap to secure the test tube before shaking to prevent any accidents.
Why substance stick to the test tube?
Substances can stick to the surface of a test tube due to adhesion, which is the attraction between the molecules of the substance and the molecules of the test tube material. This adhesion can be influenced by factors such as the surface properties of the test tube and the characteristics of the substance itself.
What are two safety rules you should follow when heating liquid in test tubes during an investigation?
Always wear safety goggles to protect your eyes from potential splashes or spills. Use a test tube holder to handle hot test tubes to avoid burns or injuries.
What happens to gas that is more dense than air in a test tube mouth up and mouth down?
Test tube mouth up: nothingTest tube mouth down: the denser gas can escape
What happen when you placed a lighted match near the mouth of the test tube?
It depends on what is inside the test tube. If the test tube is empty nothing will happen, if there is petrol in the test tube the petrol will ignite.
What happens when you place a lighted match near the mouth of the test tube?
It depends on what is inside the test tube. If the test tube is empty nothing will happen, if there is petrol in the test tube the petrol will ignite.
What happens when you place a lighted match near the mouth of the tube?
It depends on what is inside the test tube. If the test tube is empty nothing will happen, if there is petrol in the test tube the petrol will ignite.
What happened when you place a lighted match near the mouth of the test tube?
It depends on what is inside the test tube. If the test tube is empty nothing will happen, if there is petrol in the test tube the petrol will ignite.
What happens when you blow over the mouth of a test tube which is half filled with water?
Blowing over the mouth of the test tube will create a decrease in air pressure inside the tube. This decrease in pressure will cause the water in the test tube to rise up due to the higher pressure outside the tube. Ultimately, the water level in the test tube will rise as a result of the change in pressure.
When you are heating materials in a test tube what is very important about the mouth of the test tube?
The most important aspect of heating liquids in a test tube is to never look directly into the mouth of the test tube, as liquid may spurt out and come into contact with your eyes or face. However, if you are wearing plastic safety glasses, the substance may not harm you, depending on the type of substance you are heating.
Give the reason for flaming of a culture tube after the cotton plug has been removed and just before it is inserted?
Flaming the culture tube after removing the cotton plug and before inserting it helps to create a sterile environment by killing any potential contaminants on the lip of the tube. This reduces the risk of introducing unwanted microorganisms into the culture medium.
Placing the test tube holder near the mouth of test tube?
Like this: http://www.haines.com.au/Gee_Store/ProdImages/300-test%20tube%20holder.jpgIt just means to hold it by the top, not the bottom.
What happens when a piece of Mg ribbon is place in a test tube with Hydrochloric acid and cover the mouth of the test tube?
Metal + Acid --> Salt + Hydrogen Gas. As a result, the end product of this reaction is magnesium chloride and hydrogen gas. Covering the mouth of the test tube simply prevents the hydrogen gas from escaping, and allows you to test for its presence by using a lighted splint.
In heating chemicals in a test tube where should the mouth of the test tube point?
The mouth of the test tube should be pointed away from yourself and others to prevent any splashes or fumes from coming into contact. This is important for safety measures and to avoid any potential accidents during the heating process.
What is the process by which ammonia gas is produce at the bottom of the test tube comes in contact with the litmus paper at the mouth of the test tube?
When ammonia gas is produced at the bottom of the test tube and comes in contact with the litmus paper at the mouth of the test tube, it reacts with the water on the litmus paper to form ammonium hydroxide. This reaction changes the color of the litmus paper from red to blue, indicating the presence of ammonia gas. The ammonia gas diffuses up the test tube to reach the litmus paper due to differences in concentration.
