102 chemistry. college

Question

How many milliliters of an aqueous solution of 0.231 M iron(III) sulfate is needed to obtain 17.2 grams of the salt? 

Answer 1

For these problems, Start with an extensive variable (How much stuff) and cancel units with the appropriate factors to get to other extensive variable.

You know that you want 17.2 g Fe₂₍SO₄l) (IS from now on) and you want to know ml of a particular solution:

Units

g IS * (moles/ g IS)(liters/mole IS soln)(ml/liter) = ml of solution

1st factor iis 1/molar mass of IS

2nd factor is 1/molarity of the solution

3rd factor is the number of ml in a liter conversion factor