Question

You need to make an aqueous solution of 0.162 M iron(II) sulfate for an experiment in lab, using a 250 mL volumetric flask. How much solid iron(II) sulfate should you add?

___ grams

How many milliliters of an aqueous solution of 0.207 M copper(II) acetate is needed to obtain 7.15 grams of the salt?

____mL

In the laboratory you dissolve 24.2 g of lead nitrate in a volumetric flask and add water to a total volume of 125 . mL.

What is the molarity of the solution? ____ M

Answer 1

Moles of iron(II) sulfate we should add to 250 ml or 250/100 L = 0.25 L water to get 0.162 M solution is given by molarity*volume in L

Moles = molarity*volume in L = 0.162*0.25 L = 0.0405 moles

molar mass of iron(II) sulfate (FeSO4)= molar mass of Fe + molar mass of S + molar mass of O*4

= 55.8g/mole + 32g/mole + 16g/mole*4

= 151.8g/mole

weight of 0.0405 moles = moles*molar mass

= 0.0405 moles*151.8g/mole

= 6.15 g

So, solid iron(II) sulfate we should add = 6.15g