Author Question: A student uses 1 mL of water to wash the crystals from Crop A. Briefly discuss whether this is a ... (Read 140 times)

Jkov05 · **on:** Aug 23, 2018

A student uses 1 mL of water to wash the crystals from Crop A. Briefly discuss whether this is a good or faulty technique and explain why.

Question 2

What effect would you expect glucose to have on the boiling point and freezing point of water? Explain your answer in some detail.

Carissamariew · **Reply #1 on:** Aug 23, 2018

Answer to Question 1

This is not good technique. A small amount of cold water should be used to wash the crystals. Room temperature water will dissolve a significant amount of crystals.

Answer to Question 2

Because glucose completely dissolves in water and is not volatile, it behaves like a soluble, non-volatile impurity in water. The overall vapor pressure of the solution is decreased leading to a higher boiling point at atmospheric pressure and a lower freezing point, which is fairly independent of the external pressure.