Which of the following would form a precipitate in a reaction?
LiCl
ZnSO4
NaOH
CaSO4

NaOH

Explanation:

Precipitation reaction can be used in wastewater treatment. When a contaminant forms an insoluble solid, then we can use this reaction to precipitate out the contaminated ions. In wastewater, a frequent presence of heavy metals can be found such as compounds of sulphide and hydroxide. So, we can add a source of hydroxide that is soluble (NaOH Or Na2S) that will result in a precipitation reaction.

periodic trends is an atom that gets larger as the number of electronic shells increase, the radius of atoms increases as you go down a certain group in the periodic table of elements. in general, the size of an atom will decrease as you move from left to right of a certain period.

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.