C10 - WHOLE TOPIC GCSE ORGANIC CHEMISTRY (GCSE CHEMISTRY ONLY)
Summary
TLDRThis educational video delves into organic chemistry, focusing on carbon-containing molecules like esters, alcohols, and alkenes. It explains alkene reactivity due to double bonds, contrasting it with saturated alkanes. The video covers how alcohols are made through fermentation, their combustibility, and how they form alkalis with alkaline metals. It also discusses oxidation of alcohols to carboxylic acids, the weak acidic nature of carboxylic acids, and ester formation with their characteristic smells. The lesson aims to simplify complex organic reactions for better understanding.
Takeaways
- 🌐 Organic chemistry focuses on molecules containing carbon.
- 🔍 Alkenes are more reactive than alkanes due to their double bonds.
- 🧪 The bromine test is used to identify alkenes, changing color from orange to colorless.
- ➕ Alkenes can undergo addition reactions, such as with bromine or hydrogen.
- 📝 The molecular formula for ethene (an alkene) is C2H4.
- 🍾 Alcohols contain the -OH functional group and are key in fermentation processes.
- 🔥 Alcohols are highly combustible, producing carbon dioxide and water upon combustion.
- 🧪 Alcohols react with alkaline metals to form strong alkalis, like sodium ethoxide.
- 🍇 Oxidation of alcohols can lead to the formation of carboxylic acids, affecting taste in beverages.
- 🍎 Esters have distinctive smells and are formed through the reaction of an alcohol with a carboxylic acid.
- 📖 Naming esters involves placing the alcohol name first, followed by the carboxylic acid with 'oate' at the end.
Q & A
What is the main focus of the video script?
-The video script focuses on explaining organic reactions involving molecules that contain carbon, such as esters, alcohols, and alkenes.
Why are alkenes more reactive than alkanes?
-Alkenes are more reactive than alkanes because they contain double bonds, which means their carbons are not saturated and can readily undergo addition reactions.
What happens when bromine is added to an alkene?
-When bromine is added to an alkene, an addition reaction occurs where the bromine atoms add across the double bond, resulting in a color change from orange to colorless.
How can you convert an alkene back to an alkane?
-An alkene can be converted back to an alkane by adding hydrogen to it, a process known as hydrogenation.
What is the molecular formula for ethene?
-The molecular formula for ethene is C2H4.
What is the general formula for alkenes?
-The general formula for alkenes is CnH2n.
What is the functional group present in alcohols?
-The functional group present in alcohols is the hydroxyl group (OH).
How are alcohols typically produced?
-Alcohols are typically produced through a process called fermentation.
What happens when an alcohol is oxidized?
-When an alcohol is oxidized, it can become a carboxylic acid, which can give a musty or vinegary taste.
What is the molecular formula for ethanol?
-The molecular formula for ethanol is C2H6O.
How do esters get their distinctive smells?
-Esters have distinctive smells due to their chemical structure, which can vary widely, leading to different odors such as those resembling fruits.
What reaction is used to make esters?
-Esters are made through the reaction of an alcohol with a carboxylic acid, resulting in the formation of an ester and water.
How are esters named in organic chemistry?
-Esters are named by taking the name of the alcohol and placing it first, followed by the name of the carboxylic acid with the 'oic' ending replaced by 'oate'.
Outlines
🔬 Organic Reactions and Carbon Molecules
The video script introduces organic chemistry, focusing on molecules containing carbon such as esters, alcohols, and alkenes. The instructor explains how these molecules react differently due to the presence of functional groups. Alkenes are highlighted for their reactivity due to the presence of double bonds, which allow for addition reactions. The instructor demonstrates how alkenes can be tested with bromine, which turns from orange to colorless upon reaction, and how alkenes can be converted back to alkanes by adding hydrogen. The importance of alkenes in industry due to their reactivity is emphasized. The script also briefly mentions the molecular formulas for alkenes and introduces other functional groups like alcohols, carboxylic acids, and esters.
🍷 Alcohols: Properties, Reactions, and Fermentation
This section delves into the properties and reactions of alcohols. Alcohols are described as highly combustible, capable of producing carbon dioxide and water upon combustion. They can also form strong alkalis when reacted with alkaline metals. The script explains the fermentation process, crucial for producing consumable alcohols and hand sanitizers. It also covers the oxidation of alcohols, which can lead to the formation of carboxylic acids if left exposed to air or treated with an oxidizing agent like potassium dichromate. The importance of sealing alcohol containers to prevent oxidation and the resulting musty taste is highlighted. The script also touches on the weak acidic nature of carboxylic acids and their reactions with bases and metal carbonates.
🍎 Esters: Formation, Naming, and Distinctive Smells
The final paragraph discusses esters, which have distinctive smells that can range from sweet to fruity. The instructor explains how esters are formed through a reversible reaction between an alcohol and a carboxylic acid, resulting in an ester and water. The script provides an example of ester formation using ethanol and propanoic acid to produce ethyl propanoate and water. The process of naming esters is also covered, where the alcohol part is mentioned first, followed by the carboxylic acid part. The instructor encourages viewers to engage with esters in a lab setting to experience their diverse aromas and concludes the video with a call to like and subscribe for more content.
Mindmap
Keywords
💡Organic Chemistry
💡Alkenes
💡Functional Groups
💡Esters
💡Alcohols
💡Carboxylic Acids
💡Fermentation
💡Oxidation
💡Combustion
💡Naming Conventions
Highlights
Organic chemistry focuses on molecules containing carbon.
Different molecules with carbon such as esters, alcohols, and alkenes are discussed.
Reactions of these molecules are defined by other elements combined with carbon.
Alkenes are more reactive due to their double bonds and can add substances to their carbons.
Bromine's reaction with alkenes is used as a test, changing color from orange to colorless.
Alkanes are saturated and less reactive compared to alkenes.
Alkenes' reactivity makes them more useful in industry for modifying carbon structures.
Alkenes follow the general formula CnH2n.
Alcohols contain an OH functional group and are highly combustible.
Ethanol, a common alcohol, is found in beverages and has the molecular formula C2H6O.
Carboxylic acids have the functional group COOH and include ethanoic acid.
Esters have a generic formula with C-O-O-R and ethyl ethanoate is an example.
Alcohols can be produced through fermentation, a process used in beverages and hand sanitizers.
Alcohols react with alkaline metals to form strong alkalis, such as sodium ethoxide.
Oxidation of alcohols can produce carboxylic acids, affecting the taste of wines if left open.
Carboxylic acids are weak acids and do not fully dissociate in water.
Esters have distinctive smells and can be made by reacting an alcohol with a carboxylic acid.
Naming esters involves placing the alcohol name first, followed by the acid name.
Transcripts
hi guys it's your science teacher here
back with another video
this time is all about organic reactions
organic chemistry is a specific type of
chemistry
looking into molecules that contain
carbon
and in today's lesson what we're going
to do is we're going to look at
different
molecules that contain carbon such as
esters
alcohols and alkenes and look
how they react their reactions are
actually defined by other things
combined
in there other than carbon as well so
we're going to have a look at
how changing functional groups can uh
mess up the properties
and make them react a bit differently
here i've got an alkene and i can tell
i've got an alkene because of the double
bonds okay
if i was to do it properly i'd actually
add my hydrogens on
and that's now ethene um
and alkenes are more interesting than
alkanes because the fact
the double bond means they're more
reactive i can add things onto them
carbons they are not saturated
like alkanes meaning all the carbons are
used up in bonding
so this makes them highly reactive and i
can add things
to the double bonds okay
for example here's his generic reaction
just x and y but
i could substitute that in for a real
molecule such as bromine for example
and this is the reaction we use to test
for alkenes
because bromine on its own is
orange and you you might remember that
from looking at bromine water in a lab
and when you add that to ethene what
happens is
the bromine will add on where the double
bond was
and now i have
dibromoethane antibromoethane is
actually colourless so in this reaction
you would see a change in colour going
from orange
to colourless it isn't just bromine i
can add
to my carbons i could also add hydrogen
if i wanted to and convert it straight
back to being an alkane
and that would just like they look like
this with me making
ethane instead but because of the
alkenes reactivity
that makes them a lot more useful than
alkanes because i can change what is on
my carbons whereas i can't do that with
my alkanes remember
that that is saturated it's hard to
control where i add my functional groups
if i've got
functional groups which i want to add so
that's why alkenes are often more useful
in industry
so so far we've looked at alkenes and we
know that an
alkene has the formula c double bond
c and we'll just draw ethane just for an
example
uh here and the molecular formula
for that would look c2h4 that's how
you'd write it out
remember that alkenes have the general
rule of
cnh2 like that
but we aren't just going to stop at
alkenes we're going to learn about some
other
functional groups and the first one
we're going to look at is alcohols
and alcohols have the functional group
o h onto the chain
so if i was to draw an alcohol i'll draw
ethanol which is
alcohol the stuff that you find in
beverages all over the country it looks
like that and this is just ethanol that
i've drawn out
ethanol would have the molecular formula
c2 h6o
we don't just stop at alcohols either
we're going to look at carboxylic acids
as well
and carboxylic acids have
the generic addition of cooh
and what that looks like in real life is
this double bond o o h
and then this is actually ethanoic
acid and what that would look like
written down as a molecular formula
is c2 h4
and the last one we're going to look at
is esters
which have the generic formula with c
o o r and i'll tell you what the r group
stands for
i'll draw out the formula of ethyl
ethanoate
which should look like this c h h
h c and then there's a double bond up
here
and then there's a single bond to an
oxygen here and then the chain continues
c
h2 and then ch3
like that and writing out the molecular
formula
would just look like this c for
h eight and then
o two
and i'll go over how to name esther's a
little bit later on in the video
they're quite tricky to name
we're going to look at alcohols now and
we're going to look at
how they react and how we can make
alcohols as well so we can make alcohols
using a process called
fermentation and this is the process we
use
in order to make alcohol that we consume
in beverages or that we use in hand
sanitizers so fermentation
is an incredibly important process
alcohols have a few really cool
properties as well one being that
they're highly combustible
that means that they burn very well and
generically
from the combustion we will make the
products
carbon dioxide and water
just like when we were looking
at alkanes and combusting them as well
you can also make some pretty strong
alkalis
using alcohols as well um
alcohols react similarly with to water
when you add an alkaline metal with them
and it will make a strong alkaline
when you add a alcohol
to it um now the naming of it it would
be a
sodium
alkoxide for example if i was to add
ethanol to sodium it would make sodium
ethoxide
and my other product is hydrogen
gas
the last reaction we're going to look at
is one called oxidation
and if we leave an alcohol
uh in the air actually it will
uh become oxidized however you could
speed this uh reaction up by adding an
oxidizing agent like potassium
dichromate
and what this oxidation will produce is
a carboxylic acid
this is why when you have an alcohol
you have to put the lid back on uh say
if you had wine
you put the lid back on because of the
fact it will become a carboxylic acid if
you leave it out and that's what gives a
wine kind of like a musty taste
so that's why it's important for wine
manufacturers to make sure their lids
are sealed tight
and that's why people taste the wine
before their meal is because of the fact
um if it's become too oxidized it will
start to taste
like ethanoic acid the vinegary taste
you don't have to remember all the
balanced equations for these reactions
you just have to remember
the general scheme of these reactions so
an alcohol
if it's oxidized will become acids
and an example would be if i had
propanol and i left it out in the air or
added potassium dichromate
i would get propanoic acid
carboxylic acids are known as weak acids
because they do not
fully dissociate what that means
is that they do not fully dissociate to
make h plus ions if i was to show you
what i mean by that if i draw out
uh ethanoic acid and
what happens when you add ethanoic acid
to water
is this uh reversible reaction
and it produces h plus ions however
it doesn't fully go all the way uh to
the right the reaction it's reversible
and ethanoic acid is reformed and so the
h
plus is not fully dissociated and that's
why it's known as
a weak acids carboxylic
acids will react like usual acids if i
add
my carboxylic acid to a base uh
if i had it to say a metal carbonate
then
uh what i'll get is the same type of
reaction
i will make my salt which would be in
this case
ch3coo
i will make water and i will also make
carbon dioxide because if you add a
metal carbonate
to an acid these are always my products
and all i need to do to balance this
equation
actually is just put two in front of
each one of them
esther's are really cool because they
have a distinctive smells you can um
actually maybe in a lab your teachers
might have
let you smell some different esters they
often have quite sm
sweet smells uh they're often very
different from one another some esters
smell like
apples some like pears so they're really
fun to actually play with in the lab
and to make an esther what you need to
do is you need to have an alcohol
and add it to a carboxylic acid
and you make for yourself
a ester and water and this is a
reversible reaction if you add an ester
to water you will make
a carboxylic acid and an alcohol so
let's see what one of these
reactions would look like in real life
if i had ethanol for example and i was
added to
propanoic acids what i would
make ethyl propanoate and
water and i said i'd talk to you a bit
about how to name
esters so i'll do that now what you do
is you take
the alcohol and that always goes at the
start with isle at the end
and then you take your carboxylic acid
and that goes at the end with 08 at the
end
i'll just do one more example so you can
see what i mean if i have butanol
and i have ethanoic acid
this time what i will make is
butyl
ethanoa and water
thank you for watching this screencast
uh i hope you enjoyed the video
please remember to drop it a like and
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content that i'm bringing out
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