25. why does increasing concentration usually increase reaction rate?

There are more particle collisions when increasing concentration. This causes an increase in reaction.

Hope this helps you!

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.