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 fecl₃ are in the hydrated sample? ? mol fecl₃ hint: convert mass of anhydrous fecl₃ to moles.

Explanation:

Step1: Find molar mass of \(FeCl_3\)

Molar mass of \(Fe = 55.85\space g/mol\), \(Cl = 35.45\space g/mol\).
Molar mass of \(FeCl_3 = 55.85 + 3\times35.45 = 55.85 + 106.35 = 162.2\space g/mol\).

Step2: Calculate moles of \(FeCl_3\)

Mass of anhydrous \(FeCl_3 = 6.00\space g\).
Moles \(=\frac{\text{mass}}{\text{molar mass}}=\frac{6.00}{162.2}\approx0.0370\space mol\).

Answer:

\(0.0370\) (or approximately \(0.037\))