02 Ethyne Gas
Summary
TLDRThis educational video demonstrates the preparation of ethyne gas in a laboratory setting. The process begins with calcium carbide and deionized water in a flask, generating ethyne gas and calcium oxide. To purify the gas, copper sulfate and sulfuric acid are used. The gas is collected over water and tested for unsaturation using potassium permanganate and bromine water, which decolorize in the presence of ethyne. The video concludes with a flame test to confirm the presence of ethyne, showcasing a successful experiment.
Takeaways
- đŹ The experiment demonstrates the preparation of ethyne gas, which consists of two carbon atoms triple-bonded with two hydrogens.
- đ§Ș Calcium carbide reacts with water to produce ethyne gas and calcium oxide as a by-product.
- đ§ Deionized water is used in the reaction to ensure purity of the ethyne gas produced.
- đ The setup includes a doctor flask, dropping funnel, and a gas collection jar to facilitate the reaction and collection of ethyne gas.
- đ Copper sulfate and sulfuric acid are used to remove impurities from the ethyne gas.
- đŹ The presence of an unsaturated compound is confirmed through the decolorization of potassium permanganate and bromine water.
- đ„ A flame test is conducted to definitively test for the presence of ethyne gas, which burns with a distinctive flame.
- đ§âđŹ Safety precautions are emphasized, such as wearing a lab coat and conducting the experiment in a fume hood.
- â±ïž The reaction is initiated by adding water to the calcium carbide in the flask, and the gas is collected once the air is displaced.
- đ The script provides a detailed step-by-step guide for conducting the experiment, including the use of specific chemicals and apparatus.
Q & A
What is the main objective of the practical described in the script?
-The main objective of the practical is to prepare ethyne gas.
What is the molecular structure of ethyne gas?
-Ethyne gas has a molecular structure with two carbons bonded by a triple bond and each carbon is also bonded to a hydrogen atom.
What are the chemicals used to produce ethyne gas in the practical?
-Calcium carbide and deionized water are used to produce ethyne gas.
Why is copper sulfate mixed with sulfuric acid used in the preparation?
-Copper sulfate mixed with sulfuric acid is used to remove impurities from the ethyne gas.
What is the purpose of the beehive in the apparatus setup?
-The beehive is used to displace water and collect the ethyne gas.
How is the ethyne gas collected in the practical?
-Ethyne gas is collected by filling glass jars with water, inverting them in a water trough, and then connecting them to the gas outlet of the reaction flask.
What is the purpose of the flame test in the practical?
-The flame test is used to confirm the presence of ethyne gas by observing the color of the flame.
What is the significance of the decolorization of bromine water in the practical?
-The decolorization of bromine water indicates the presence of an unsaturated compound, as ethyne gas reacts with bromine, causing the solution to lose its color.
Why is it important to remove the displaced air before collecting ethyne gas?
-It is important to remove the displaced air before collecting ethyne gas to ensure that the collected gas sample is pure and not contaminated with air.
How is the reaction initiated between calcium carbide and water?
-The reaction is initiated by allowing water to drop onto the calcium carbide in the flask, which produces ethyne gas and calcium oxide as a by-product.
What safety precautions are mentioned in the script during the practical?
-The script mentions wearing a lab coat and conducting the flame test in a fume cupboard as safety precautions.
Outlines
đŹ Preparing Acetylene Gas in a Lab
The video script describes a laboratory procedure for producing acetylene gas. The setup involves a doctor flask with a dropping funnel and a delivery tube leading to a collecting jar. Calcium carbide is used as the solid reactant, and deionized water is added to react with the calcium carbide to generate acetylene gas and calcium oxide as a by-product. To purify the gas, copper sulfate mixed with sulfuric acid is used to remove impurities. The process begins with adding calcium carbide to the flask and then slowly introducing water to initiate the reaction. The initial gas bubbles are displaced air, which is not collected. Once the air is cleared, the acetylene gas is collected in glass jars that have been filled with water to displace the gas. The video also mentions the importance of conducting a flame test to confirm the presence of acetylene, which is indicated by a distinctive flame color.
đ§Ș Testing for Unsaturated Compounds and Acetylene Gas
This part of the script focuses on testing for unsaturated compounds using potassium permanganate and bromine water. The procedure involves bubbling the acetylene gas through a solution of potassium permanganate, which should decolorize if an unsaturated compound is present. The script also describes a method to check the decolorization effect by comparing it with a control test tube. The decolorization of the potassium permanganate solution indicates the presence of an unsaturated compound, such as acetylene. Additionally, the script describes a test with bromine water, where the acetylene gas is bubbled through it, causing a reaction that leads to decolorization due to the addition of bromine across the triple bond of acetylene. The script concludes with the preparation of a sample of acetylene gas for a flame test, which is a definitive test for the presence of acetylene, confirmed by the gas producing a specific flame color when ignited.
Mindmap
Keywords
đĄEthane gas
đĄCalcium carbide
đĄTriple bond
đĄApparatus
đĄDeionized water
đĄCopper sulfate
đĄSulfuric acid
đĄFlame test
đĄDecolorization
đĄUnsaturated compound
Highlights
Introduction to the preparation of ethyne gas with a model of its molecular structure.
Description of the apparatus setup, including a doctor flask, dropping funnel, and collecting jar.
Use of calcium carbide as the solid chemical to produce ethyne gas.
Deionized water is used in the preparation process to ensure purity.
The necessity of copper sulfate and sulfuric acid to remove impurities from the ethyne gas.
Procedure for adding chemicals into the flask, including calcium carbide and deionized water.
Explanation of the gas collection process and the importance of removing air from the apparatus.
Observation of the reaction as calcium carbide reacts with water to produce ethyne gas and calcium oxide.
Demonstration of the decolorization test using potassium permanganate to confirm the presence of an unsaturated compound.
Use of bromine water to test for the presence of a triple bond in the ethyne gas.
Observation of the decolorization of bromine water as ethyne gas reacts with it.
Preparation for the flame test to definitively identify the presence of ethyne gas.
Safety precautions taken during the flame test, including the use of a fume hood and a lighter.
Successful production of ethyne gas confirmed by the characteristic flame test.
Transcripts
[Music]
in his practical here today we're going
to prepare ethan gas so here is the
model of ethyne gas two carbons bonded
by a triple bond with two hydrogens
later end so north prepared etang gas
you need to apparatus here I have in
front to me a doctor flask with a
dropping form and addrational head into
a collecting jar so first of all in
order to do this practical look at the
chemicals the solids were going to make
the Etan gas out of is calcium carbide
which I'll be putting in today okra
flask I'm going putting deionized water
in here into the dropping funnel and
then when you're preparing etang gas a
lot of impurities so in order to remove
that impurities you need a certified
copper sulfate so I have a copper
sulfate mixed with sulfuric acid
institution here I'll be adding this
into the threshold bottle I got pour the
copper sulfate in my rationale bottle
roughly 3/4 filled and then if I put my
dress on head in here make sure to clamp
it up put the Thresher headed to the
solutions so sure that you go to the
bottom of the container and then the
tube because the bottom to entertainer
the other end of this rubber tubing must
be connected on to my book nor flask so
I put your rubber on to your book the
flask and now we've got all the
apparatus complete so addition of
chemicals into the container the Bhakra
flask I click on my calcium carbide the
calcium carbide comes in large lumps so
put that in the bottom of my container
again it doesn't really matter how much
you add in possibly 20 or 30 grams and
for a funnel back on the top of the
container and I'm using deionized
deionized water so here I have a beaker
of the ionized water make sure the top
is closed before you start
now reactors ready to go and now we want
where we're going to connect glass we're
gonna get our beehive into our water
trough there's a beehive and our rubber
tubing goes into the end of the beehive
and the gas is going to come out or
beehive and be connected in our glass
jars so with the glass jars I've got
these previously filled full of water to
move the water trough and slide the
glass off the bottom and your apparatus
is ready for collection however if I
fill the glass here now if I start
reaction at this start stage I've got
air in all of these voids inside here
that air will be displaced into a glass
jar so remove the tube until you're
ready to collect its gas and then we're
ready to start reaction okay so can I
open the tap here the water is going to
drop down to cut some carbide the CHC to
producing Etan gas and calcium oxide as
a by-product
so I going to gently let some water into
the container and we'll start to see
bubbles then produce really quickly this
actually bubbles of gas comic artists
tube this bubble is the displaced air
that's in the container so we don't
collect the first few drops of gas now
that all the displaced air is gone I can
now collect the ethane gas for the flame
tests like breathing wadding the
knee-high boot you see the bubbles
coming up here
it's placing the water downwards so now
my glass jar is full of a defy gas I
will now be able to my flame tests on
the efi gas which is the definitive test
to see what I've got neat I'm present or
not before we actually do the flame test
I'm first of all I'm going to do the
demonstration of the check to see
whether I've got an unsaturated compound
so remember this is it check to see
we've got an unsaturated compound not to
check for eaten gas to check for eaten
gas is solely the flame test for tests
we use some test tubes so into test tube
one I'm going to put a simple magnet and
properly certified potassium pregnant
there's purple solution here
it's also advisable to have a test test
tube as well so you can sit short a
color before you do the reaction
that's my detachment magnet test Edition
is now ready now then with bromine water
again is my test solution I'm gonna put
it into a test you add the Roman water
test you and another solution
I'll get a test solution ready as well
so I can see the corner before hunter
stop controlling water for 400 so in
this decolorization practical you Bobble
eaten gas true the Siddha five
attachment magnet the magnet the magnet
ease in the macro magnet goes from plus
seventy plus 2 and it gets decolorized
so open your present test you to tube
into it and if you have an unsaturated
compound you will get the chlorination
of potassium for magnet very gently
and probably the eat on gas to
detachment wagon it as the eat on gas
reacts with the magnetic it'll torrent
colorist let that continue for a while
I see the advantage now of having the
before color ready you can see if this
is decolorizing in front of our eyes
here test to is a decolorization of
roaming water but here absent bromine
water I'm going to bubble my gas shoot
the roaming water the action of slow
down so I need to add some more water
so my gas there's an additional reaction
occurring the bromine is adding across
to the triple bond and putting drawings
onto the compound and this should
decolorize a solution this takes a
little bit longer go through but again
as a reaction proceeds we can look at a
test solution and you can see the
decolorization is occurring now what I'm
going to do is take out my gas jar so
I'm going to snip this glass disk
underneath before a little jar out of
the water and now we've got my sample of
eaten gas for the flame test so
professor if the fume cupboard
always make sure your lighter is list
before you remove the glass disk
so we see the [Â __Â ] flame definitely we
have produced a tying us
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