Question

SEPARATION OF A MIXTURE OF SOLIDS 4. Define the terms "sublimation" and "decantation." 5. Consider that you started with a 3.506 g sample of a mixture containing NH,CI, NaCI, and Sio, and sublimed away 0.750 g of NH·CL when you removed all of Naci by dissolving in water, 1.284 g of SiO2 was present in the evaporating dish. What was the mass percentage of NaCl in the mixture? Show all work.

Answer 1

Sublimation:

Phase transition of a solid directly into gas without passsing through intermediate liquid phase.

Decantation:

Process of separation of a mixture by removing liquid layer, generally one from which solid has settled down.

W(total) = W(NaCl) + W(SiO2)+ W(NH4Cl)

3.506 = W(NaCl) + 1.284 + 0.750

W(NaCl) = 1.472 g

Mass percentage of NaCl = 100 ×W(NaCl)/W(total)

= 100 × 1.472/3.506

= 41.99