Hello, in which chemical reaction is the highest sedimentation rate observed? The chemical reaction must be between two true solutions. Thank you. 

20 minutes ago, anastasiap said:

Hello, in which chemical reaction is the highest sedimentation rate observed? The chemical reaction must be between two true solutions. Thank you. 

I presume you mean rate of precipitation. 

Rates of reaction in solution depend on various factors in addition to the reactants involved, notably concentration and temperature. So I don't think it is possible to answer your question.  But @John Cuthber may be able to provide some examples of reactions in which a product precipitates rapidly. My inorganic chemistry is too rusty for me to able to do that without looking things up. Though, as I recall, BaSO4 precipitates quickly from mixing suitable solutions e.g. BaCL2 and Na2SO4.