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Polymer

Ari Ben Canaan

Its quite obvious that A is incorrect.

However, I cant seem to understand how B or C are correct.

Original post by Ari Ben Canaan

Its quite obvious that A is incorrect.

However, I cant seem to understand how B or C are correct.

Polymers MUST be larger then the monomers that make them up, hence their relative moleclar masses are much larger.

In addition polymerisation:

nX --> -[X]-_n

As you have 1 mole of monomer which can theoretically polymerise, then the length of the polymer can be up to 6 x 10²³ units long. If this is the case then you would have only one particle or 1/(6 x 10²³) moles

And as it gets bigger its number of moles gets smaller.

Hence the answer is anything (considerably) less then 1

Reply 2

Ari Ben Canaan

Original post by charco

...

Okay... I see.

One other thing.

Lets say I have a organic molecule with 5 C=C bonds.

I've heard of a rule where 2ⁿ = no. of cis-trans isomers, where n = no. of C=C bonds.

Is this rule true and can I apply it to any such situation ? Are there limitations ?

Reply 3

charco

Study Forum Helper

Original post by Ari Ben Canaan

It seems likely when the dbs are in the middle of a chain and not consecutive (C=C=C) but can't be 100% true.

For example if a H₂C=C bond is at the end of a chain there are no geometric isomers.