Question

iron and chlorine form several different compounds, some of which are hydrated. 10.00 g of a hydrated fecl₃ compound was decomposed, leaving 6.00 g of anhydrous fecl₃. how many moles of h₂o are in the hydrated sample? ? mol h₂o hint: how could you figure out how much water was lost from the original sample?

Explanation:

Step1: Find mass of water

The mass of the hydrated compound is 10.00 g and the mass of anhydrous \(FeCl_3\) is 6.00 g. So the mass of \(H_2O\) is \(10.00 - 6.00 = 4.00\) g.

Step2: Calculate moles of \(H_2O\)

The molar mass of \(H_2O\) is \(2\times1 + 16 = 18\) g/mol. Moles = mass / molar mass, so moles of \(H_2O\) is \(\frac{4.00}{18} \approx 0.222\) mol.

Answer:

\(0.222\) (or more precisely \(\frac{2}{9} \approx 0.222\))