Question

16. A mineral named antarcticite (because it is found from a small pond in Antarctica) gave
the alowing data after analysis:
Ca = 17.5%, Cl = 32.7%, H,0 = 49.2%
What is the simplest formula of the compound?


----PLEASE GUYS SOLVE IT
STEP BY STEP---​

Answer 1

1) Let us assume the weight of mineral be = 100 g

Then, weight of Ca = 17.5 % of 100 g = 17.5 g

Weight of Cl = 32.7 % of 100 g = 32.7 g

Weight of H2O = 49.2 % of 100 g = 49.2 g

2) Convert it into their respective molar amount

Ca = 17.5 g / 40 g mol-1 = 0.4375 mol

Cl = 32.7 g / 35.5 g mol-1​ = 0.9211 mol

H2O = 49.2 g / 18 g mol-1 = 2.733 mol

​3) Divide the molar amount by the least value, which is 0.4375 in present case, in order to get a whole number ratio

Ca = ​0.4375 / ​0.4375 = 1

Cl = 0.9211 / ​0.4375 = 2

H2O = 2.733 / ​0.4375 = 6

Hence, the empirical formula or the simplest formula of the mineral antarcticite is CaCl2.6H2O.