Colour by design booklet- OCR B Salters

A Booklet on the salters section Colour by design. Detailed notes following the specification. Feel free to contact via get revising mail if anything doesn't make sense to you. Also visit for further resources.

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a) Explain the term electronegativity: recall qualitatively the electronegativity trends of
in the Periodic table. Use knowledge of this to predict bond polarity and hence the
types of bonds to form between molecules/atoms.

Fluorine is the most electronegative element in the periodic table. Electronegativity increases as

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c) Describe and explain the structure of a dye molecule in terms of the chromophore and:
i) Functional groups that modify the chromophore.
ii) Functional groups which affect the solubility of the dye
iii) Functional groups that allow the dye to bond to fibres

Chromophore: The chromophore is the part…

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e) See below and chapter 12.3 + 12.4:
i) Recognize arenes and their derivatives (aromatic compounds)
ii) Describe the delocalization of electrons in these compounds.
iii) Explain how delocalization accounts for their characteristic properties (limited
to undergoing substitution rather than addition reactions.

i) Arenes are RINGS, which are stabilized by…

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g) Describe and explain the following electrophilic substitution reactions of arenes, naming
the benzene derivatives formed

i) Halogenation of the ring,

ii) Nitration,

iii) Sulfonation,

iv) Friedel-Crafts alkylating and Acylation (including use of ionic liquids).

i) Chlorine and benzene can be substituted into an arene. This reaction uses an anhydrous…

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Bezene-SO2OH + NaOH Benzene-SO3- Na+ + H2O
iv) Alkylation:

An alkyl group is added to the benzene. Benzene is warmed with chloromethane and anhydrous
aluminum chlorine (AlCl3). Methylbenzene is the product!


Benzene and an acyl chloride (or an acid anhydride) are heated together under reflux with AlCl3.


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NaNO2 (aq) + HCl (aq) HNO2 (aq) + NaCl (aq)
The nitrous acid then reacts with the arlyamine. For example:

+ HNO2 + H+
+ 2H2O
Phenylamine Bezenediazonium Ion


In a diazo coupling reaction, a diazonium salt reacts with another compound containing a
benzene ring called a COUPLING…

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Coupling with Phenols:

When a solution of the Benzenediazonium salt is added to an alkaline solution of PHENOL, a
YELLOW-ORANGE azo compound is formed:

With an alkaline solution of naphthalen-2-ol, a red azo compound is produced:

Coupling with Amines:

Diazonium salts also couple with ARYLAMINES such as PHENYLAMINE:

Many different…

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Now when light travels through a solution of metal ions surrounded by ligands, a photon of light
may be absorbed. The energy of this photon corresponds to excitation of an electron from a
low energy d orbital to a high-energy d orbital.

The frequency of the light absorbed depends on…

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The mobile phase is an unreactive gas, such as NITROGEN, called the CARRIER GAS.

The Stationary phase is a small amount of a high boiling point liquid held on a finely divided inert
solid support. This material is packed into a long thing tube called a COLUMN. The column is…



Hi, this is an AMAZING reosourse which i would use ... if i was in A2 (so i will save it for next year). do you have one for AS? i really love how u simplified it by using the spec. 

much appreciated if you could let me know if u have one for AS and how to access it :)

Thanks :D


Three years on and this is still so useful.

Thanks, James!

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