A liquid changes color as it cools and becomes solid. How can you confirm the type of change that took place?

fe 55.85 g/mol and h2o 18.02 g/mol.

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.

i think that the answer is c