Chemistry related

Question

What would be the most rapid method of preparing a saturated aqueous solution of KNO, if the solubility is known?

(A)Add the calculated amount of solute to the proper amount of water at 20 °C and wait until all is dissolved.

(B)Add to water at 20 °C a slight excess over the calculated amount of solute and water and wait until no more solute dissolves.

(C) Dissolve less than the calculated amount of solute and let some of the water evaporate at 20 degrees Celsius

(D)Add an excess over the calculated amount of solute to hot water and cool to 20 °C, with stirring.

(E) Neutralize a dilute solution of KOH with dilute HNO, and evaporate to the desired volume.

could you explain why you got that answer?

Answer 1

I believe the answer is D. Heres why...

A) This process takes some time, but would eventually get a saturated solution

B) This will take slightly less time than A because the increased concentration of salt will drive the reaction forward, but it is still not very efficient.

C) This will not produce a saturated solution.

D) Most salts dissolve much more rapidly and to a higher concentration in a warmer solution. By dissolving it at a higher temp, you are ensuring that the solution is completely saturated by the time it reaches 20 degrees. Then the solution would be quickly brought back down to temperature in an ice bath.

E) This is not efficient and would take too much time.

If you need me to clarify anything please feel free to reach out. I hope this helped :)