The materials revolution: OCR Salters B

A set of notes following the OCR B salter specification, addressing each point and trying to provide detailed revision notes. Some diagrams and mechanisms need to be looked up in relevent textbooks, the best being the Chemical Ideas textbook by the salters company!

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James Smith

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How To Use this Booklet:
This booklet has been created by addressing all the points on the OCR B
salters specification for the section, what's in medicine. I advise reading
through the Book, highlighting or underlining words written in ALL
CAPITALS. I also suggest making a spider diagram or mind map to
summarise key points and help the information here stick in your mind. You
could also draw your own images by points on this book that may help you
to remember that point.…read more

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The STRONGER the Intermolecular forces, the HIGHER the boiling point of the
polymer. Polymers with electronegative atoms (F, O or N) within them can
form Hydrogen bonds with hydrogen atoms on other chains of the polymer,
making the polymer have an increased melting point (Tm). At temperatures
above it's Tm, a polymer is a viscous fluid!
Below a certain temperature, polymers become GLASSY (brittle). This
temperature is called the GLASS TRANSITION TEMPERATURE (Tg).…read more

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This makes the polymer even more strong and dense.
Kevlar is made up of benzene rings in polymer chains!
The LONGER the chain, there are more and generally greater
intermolecular forces. This means there is a greater strength.
Note that the flexibility of a polymer depends upon the ability of the
polymer chains to SLIDE OVER one another. The stronger the IM
bonds, the less able the chains are to slide over one another...…read more

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It is important that the plasticisers added to PVC film used for wrapping food
do not dissolve into fatty foods as they may be HARMFUL to HEALTH!
Cold drawing is STRETCHING out the polymer. This makes a
polymer stronger. All polymers contain SOME crystalline
regions. The stretching of the polymer can continue until all the
chains of the polymer are aligned with one another.
Since the number of crystalline regions is increased, cold-drawing
leads to a significant increase in the polymer's strength.…read more

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R C N R'
These are formed from reactions of PRIMARY AMINES with ACYL CHLORIDES.
Amines with ONE ALKYL GROUP are called Primary amines. Secondary Amines
have TWO ALKYL GROUPS. Tertiary Amines have THREE ALKYL GROUPS and no
hydrogen atoms on the Nitrogen.
The alkyl group connected to the nitrogen names simple/low primary Amines.
Simple secondary
amines are named similarly
to primary amines, but you put the prefix DI- in
front of the alkyl group.…read more

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Amines often smell of decaying fish or rotting flesh.
Amines are SOLUBLE in water due to the fact that they can form hydrogen
bonds with water molecules. Amines with longer Alkyl groups are less soluble
as the alkyl groups disrupt the hydrogen bonding.
Amines act as BASES. Due to the lone pairs on the nitrogen, it can take place in
a dative covalent bond, donating it's electrons to H+. This means it is a H+
acceptor.…read more

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If concentrated HCl acid is used for hydrolysis instead of the base, the alcohol
and acid from which the ester was formed from are produced.
Therefore, a polyester will hydrolyse to the dicarboxylic acid and the diol from
which it was derived from!
If an amide is heated under efflux with moderately concentrated HCl, the SALT
of the amine and the CARBOXYLIC ACID are formed.…read more

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Heating with moderately concentrated alkali produces the amine and the salt
of the acid!
So in acid conditions, polyamides hydrolyse to dicarboxylic acids and diamine
(I) Describe the following reactions of amines:
(i) Neutralization by acids
As amines are BASIC, they react with acids by accepting a proton. For example:
RNH2 + HCl RNH3+Cl- (an amine salt)
The lone pair on the nitrogen atom in the amine allow the amine to accept the
proton from the acid, creating a cation (a positive charge).…read more

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J) Recall the procedure for purifying an organic solid product by
recrystallisation, and explain that the solvent used: must be one in which the
substance is very soluble at higher temperatures and insoluble, or nearly so,
at lower temperatures; is saturated by the substance at higher
temperatures, and on cooling the substance then crystallizes out, to leave
the impurities in solution.
1) Select a suitable solvent in which the desired substance is very soluble at
higher temperatures and insoluble at lower temperatures.…read more


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