C3 Organic Chemistry Flashcards
If an alcohol has 2 carbon atoms, what is the formula?
C2 H5 OH
What is the general formula for alcohols?
CnH2n+1OH.
There are twice the number of hydrogen atoms plus one and an extra OH.
What is the functional group of alcohol?
-OH
What is a homologous series?
A group of chemicals that react in a similar way because they have the same functional group. Like -OH
Name the first three alcohols?
Methanol, Ethanol and Propanol.
How are alcohols named?
Get rid of the E in the alkanes name and replace with an “ol”
What do the first three alcohols have in common?
They are flammable,
dissolve completely in water to form neutral solutions.
react with sodium to give hydrogen and alkoxides.
Give the equation for methanol burning in air.
2CH(small 3)OH + 3O(small) produce 2CO(small 2) + 4H(small 2)O
Carbon dioxide and water are produced.
Give the equation of ethanol reacting with sodium.
2C”2”H”5”OH + 2Na produces 2C”2”H”5”ONa + H”2”
How can alcohol be used as a solvent?
Methanol and ethanol can dissolve compounds that water can’t like hydrocarbons, oils and fats.
Ethanol is used in perfume and aftershave. It can mix with oils and the water.
Methylated spirit is ethanol with chemical added to it.
They can be used as fuel and can clean paint brushes.
How can alcohol be used as a fuel?
Ethanol can be used as a fuel in spirt burners. Is burns clearly and it doesn’t smell.
Ethanol can be mixed with petrol to produce fuel for cars. It is cleaner than normal petrol.
Some nations with little oil but lots of land and sunshine can grow lots of sugar Caine to produce ethanol.
This is good as the sugar cane is renewable resource.
What is the functional group of carboxylic acid?
-COOH
How do you name a carboxylic acid?
It will start with meth,eth, or prop and end with anoic acid.
What is the equation of methanoic acid ?
HCOOH
What happens when you react carboxylic acid with metal?
They produce CO2 and a salt which will end with -anoate.
Methanoic acid will form methanoate and ethanoic acid will produce ethanoate.
Give the word equation of ethanoic acid reacting with sodium carbonate
Ethanoic acid + sodium carbonate = carbon dioxide + sodium ethanoate.
Why do carboxylic acids produce less acidic solutions when mixed with water?
When the acid dissolves in water, they ionise and release H+ ions which make the acid acidic. However they aren’t completely ionised so they form weak acidic solutions. This means they have a higher pH than aqueous solutions of strong acids with the same concentration.
For example
HCl forms H+ and Cl- ions.
CH”3”COOH forms H+ and CH”3”COO- ions. Only half of the hydrogens have been ionised.
How can carboxylic acid be used in industry?
Long chained carboxylic acids with lots of carbon atoms are used is soaps and detergents.
They are used in the preparation of esters.
It is a good solvent for many organic molecules but it is seldom used as it makes the solution too acidic.
Name some more common carboxylic acids and how they are formed.
Ethanoic acid is made by oxidising ethanol. Microbes cause the ethanol to ferment. It can also be used as an oxidising agent.
Ethanol + oxygen = ethanoic acid + water.
Ethanoic acid can be mixed with water to produce vinegar.
Citric acid can get with scale and is used in fizzy drinks.
What is the functional group of esters?
-COO-
How are esters formed?
An alcohol and a carboxylic acid are put together with an acid catalyst. (Sulphuric acid is normally used )
Alcohol + carboxylic acid = ester + water.
How are the names of esters made and give an example
They names end in -oate.
The alcohol forms the first part if the esters name, and the acid forms the second part.
Ethanol + ethanoic acid = ethyl ethanoate + water.
Methanol + propanoic acid = methyl propanoate + water.
What can esters be used for and not used for?
They smell nice, sweet and fruity. They are also volatile which means they make good perfumes.
However many are flammable meaning they are potentially dangerous.
Don’t mix well with water but do mix with alcohols and organic solvents.
Some are used as ointments.
Others are used as solvents for paint, ink, glue and nail varnish remover.
What does have to be considered when using esters?
Inhaling the fumes from some of them irritates mucous membrane in the nose and mouth.
They are heavier than air and are very flammable. The can cause explosions.
In large doses some are toxic. Some people worry about the health problems.
However they aren’t as volatile or toxic as other organic solvents. They don’t produce as many toxic fumes and are replacing some solvents.
