Monday, 22 April 2013

Q 1.3: Classify the following as amorphous or crystalline solids: Polyurethane, naphthalene, benzoic acid, teflon, potassium nitrate, cellophane, olyvinylchloride, fibre glass, copper.


Classify the following as amorphous or crystalline solids: Polyurethane, naphthalene, benzoic acid, teflon, potassium nitrate, cellophane, olyvinylchloride, fibre glass, copper.
Substance type of solid
Polyurethane     Amorphous solids
Nnaphthalene   Crystalline solids
benzoic acid     Crystalline solids
Teflon    Amorphous solids
Potassium nitrate Crystalline solids
Cellophane Amorphous solids
Polyvinylchloride  Amorphous solids
Fibre glass     Amorphous solids
Copper Crystalline solids

10 comments:

  1. How do we know whether the given material is amorphous or crystalline? Could you please explain?

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    1. All polymers are crystalline. All glass except quartz is amorphous . All molecular, ionic, covalent, metallic solids are crystalline. U can only classify with their property's. (i am not an admin. but a visitor)

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    2. Look up the differences between them...amorphous solids have no form... They consist of particles of irregular shape.. The definitions will make you clear-Laxmi satyam Sai sindhu karri

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    3. Look up the differences between them...amorphous solids have no form... They consist of particles of irregular shape.. The definitions will make you clear-Laxmi satyam Sai sindhu karri

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    4. All polymers are amorphous

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    5. Definite shape -crystalline solid Irregular shape-amorphous solid

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  2. Not all Polymers are Crystalline. PC, PVC, PS, ABS, PMMA and many others are Amorphous polymers.
    Crystalline polymers form crystalline structure during liquid to solid phase transition and amorphous polymers do not form such crystalline structure during the phase transition.

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  3. It also depends on how quickly the liquid was cooled into the solid. Crystalline nature is more specific than amorphous nature. Therefore, if a liquid gets more time to cool , the setting of the particles becomes more selective, i.e. a crystalline structure is obtained. There are a few exceptions to the cases which seem to be crystalline and are not or the other way round. for example quartz is the only crystalline glass. But for most cases it is better to remember one compound from each class and its structure. That will make your job a lot easier

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