How many moles are in 5.72 grams of iron (II) chloride

0.0451 mol FeCl₂

General Formulas and Concepts:

Chemistry - Atomic Structure

Explanation:

Step 1: Define

5.72 g FeCl₂

Step 2: Identify Conversions

Molar Mass of Fe - 55.85 g/mol

Molar Mass of Cl - 35.45 g/mol

Molar Mass of FeCl₂ - 55.85 + 2(35.45) = 126.75 g/mol

Step 3: Convert

= 0.045128 mol FeCl₂

Step 4: Check

We are given 3 sig figs. Follow sig fig rules and round.

0.045128 mol FeCl₂ ≈ 0.0451 mol FeCl₂

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)