Calculate the percentage of Fluorine, Sodium and Aluminium

Mole Concept (10)

Calculate the percentage of:

  1. Fluorine
  2. Sodium and
  3. Aluminium

in sodium aluminium fluoride [Na3AlF6], to the nearest whole number. [Atomic Mass: Na = 23, Al = 27, F = 19]

Answer

Molecular weight of Na3AlF6

= (23 x 3) + 27 + (19 x 6)

= 210

(i) percentage of F = (114 x 100)/210 = 54.28% or 54%

(ii) percentage of Na = (69 x 100)/210 = 32.85% or 33%

(iii) percentage of Al = (27 x 100)/210 = 12.85% or 13%

  • Exam Year: 2020