Flashcards in Colour by Design Deck (7)
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1
Q
What is a conjugated system
A
A conjugated system has alternating single and double bonds, allowing the overlap of p-orbitals
2
Q
Colourless and coloured objects
A
Colourless objects reflect all visible light and do not absorb any
Coloured objects absorb the wavelength of the colour they appear
3
Q
What are complimentary colours
A
Two colours which combined together produce white light
4
Q
Factors affecting colour
A
- The more electrons that are delocalised in the conjugated system, the smaller the energy gap
- Smaller energy gaps result in the absorption of longer wavelengths of light absorbed
It usually takes 5 pi bonds in a conjugated system for the system to start absorbing visible light
5
Q
The geometry of benzene
A
- The benzene ring is a regular, planar hexagon
- All the bond angles are 120 degrees
- All the carbon-carbon bonds are the same length
6
Q
Stability of delocalised structures
A
The more delocalised a system is, the more stable it is
7
Q
Benzene reaction with bromine
A
Electrophilic substitution with an iron catalyst to form bromobenzene and HBr