How to make a saturated solution of sodium chloride?

1 Answer
May 23, 2018

Answer:

How do you make a saturated solution of anything....?

Explanation:

Saturation specifies an equilibrium condition, that is poorly understood at even undergraduate level. By definition , a saturated solution contains an amount of solute that would be equal to that amount which would be in equilibrium with undissolved solute. An examiner would be quite justified in marking an answer that proposed that the ….

#"solvent holds all the solute that it can in a saturated solution"#

......….as incorrect...

And we could represent a saturated solution....

#NaCl(s)stackrel(H_2O)rightleftharpoonsNa^+ + Cl^-#

We usually quote a temperature, because a hot solution can normally hold more solute than a cold one. In this scenario, the solubility of sodium chloride is rather insensitive to temperature.

And so get some water, approx. #100*mL#, and add approx. #40-50*g# of salt.... Not ALL of the salt will go up into solution...and here the equilibrium condition is satisfied... When the supernatant solution is decanted or filtered you gots the required #"saturated solution"# of #NaCl(aq)#.

Sorry to go on, but these definitions are SPECIFIC, and yet it seems to cause a lot of confusion...