9 grade science> Chemestry: Collaids: How is multimolicula...

Chemestry: Collaids:

How is multimolicular collaid lyohilic?

I am studying in 9^th std and i am having some doubts in collaids.

In collaids there are 2 types on the bases of molecules. Multimolicular and macromolicular. and 2 types on the basis of nature lyophilic and lyophobic.

Multimolicular collaid is lophilic in nature. But how Multimolicular collaid should be lyophobic nature because it is the lyophobic collaid which attrcts each other and be heavy and so is instable.

Thanks in advance

pranav taysheti , 11 Years ago

Grade 9

4 Answers

Anjali Ahuja

Last Activity: 11 Years ago

hello pranav..
Yes there are multimoleculer and macromoleculer colloids.
Multimoleculer colloids are lyophiilic (liquid loving) in nature on an average.
Generally in this type there is occurence of lyophillic as well as lyophobic portion in the same molecule. This the aggregates of ions and molecules with lyophobic and lyophillic parts are called micelles. Micelles are of colloidal dimensions though the individual ion or molecules may not be of colloidal dimension. In figure; hydrophillic is water(liquid) loving and hydrophobic is water(liquid) repelling

Approved

pranav taysheti

Last Activity: 11 Years ago

Sir. but arent the miscelles the third type of collaids. According to book miscelles are diferent than multimolicular collaid.

Anjali Ahuja

Last Activity: 11 Years ago

Yes you are right If we widely categorise the colloids there is third category called associated colloids in which micelles are included. Here in multimoleculer colloids the aggregates are like micelles but these are of atoms or small molecule which are held together by Van der Waal forces. For example sulphur sol consists of colloidal particles which are aggregates of S8 molecules.