A compound containing Na, S, H, and O where, Na =14.28 %, S = 9.92%, H = 6.2% and the rest are O. The molecular mass of the compound is 322. Calculate the molecular formula of compound considering all H atoms are present as water of crystallization?
The last part which explains that H is present as the water of crystallization is a bit confusing for me.
The last part which explains that H is present as the water of crystallization is a bit confusing for me.
1 Answer
Warning! Long Answer. The molecular formula is
Explanation:
Step 1. Calculate the empirical formula
The empirical formula is the simplest whole-number ratio of atoms in a compound.
The ratio of atoms is the same as the ratio of moles.
So, our job is to calculate the molar ratio of
Your compound contains 14.28 %
Assume that you have 100 g of sample.
Then it contains 14.28 g of
From this point on, I like to summarize the calculations in a table.
The empirical formula is
Step 2. Calculate the molecular formula of the compound
The empirical formula mass of
The molecular mass is 322 u.
The molecular mass must be an integral multiple of the empirical formula mass.
The molecular formula must be the same as the empirical formula.
Step 3. Calculate the water of crystallization
If all the
The molecular formula is