Question

An inorganic compound contains 16.1% sodium, 4.2% carbon, 16.8% oxygen and 62.9% water of crystallization. Calculate the emperical formulae of the compound.

Answer 1

Answer:

Na₂CO₃(H₂O)₁₀

Explanation:

The best way to do this is to create a table with sodium, carbon, oxygen and water along the top. Then down the side up percentage, Ar, Mass/Ar and ratio.

The Ar of sodium - 23, carbon - 12, oxygen - 1.05 and water - 18.

Mass/Ar of sodium - 0.7, carbon - 0.35, oxygen - 1.05 and water - 3.494.

To find the simplest ratio find the smallest number (0.35) then divide the rest of the numbers by this. Sodium - 2, Carbon - 0.35, Oxygen - 3 and water - 10.

Then you just place it into the formula Na₂CO₃(H₂O)₁₀.

Hope this has helped.

Answer 2

Answer:

16.1 x 1 mol/23 = 0.7

4.2 x 1 mol/12 = 0.35

16.8 x 1 mol/16 = 1.05

62.9 x 1 mol/18 = 3.494

Therefore, 0.7/0.35 = 2

0.35/0.35 = 1

1.05/0.35 = 3

3.494/0.35 = 10

Explanation: