Question

Q2. Write a note on Critical Solution Temperature.

with breif explanations   

Answer 1

the temperature at which complete miscibility is reached as the temperature is increased or in some cases it is decreased. The solutions used are two liquids that are partially miscible under ordinary conditions.

the critical solution temparatureis of two types:-

1. Upper critical solution temparature:- it is a critical temparature above which the components of a mixture are micible in all proportions. The word upper indicates that it is an upper bound to a temperature range of partial miscibility, or miscibility for certain compositions only. For example, hexane-nitrobenzene mixtures have a upper critical solution temp of 19 °C, so that these two substances are miscible in all proportions above 19 °C but not at lower temperatures.

2.Lower critical solution temparature:-it is a critical temparature below which the components of a mixture are micible for all compositions.  The word lower indicates that it is a lower bound to a temperature interval of partial miscibility, or miscibility for certain compositions only. triethylamine-water has an lower critical solution temp of 19 °C, so that these two substances are miscible in all proportions below 19 °C but not at higher temperatures.