Question

a student weighs out a 3.78 g sample of , transfers it to a 125 ml volumetric flask, adds enough water to dissolve it and then adds water to the 125 ml tick mark. what is the molarity of iron(ii) acetate in the resulting solution?

Answer 1

Okay, let's solve this step-by-step:

* We are given a 3.78 g sample of iron(II) acetate that is dissolved in water in a 125 ml volumetric flask

* We need to find the molarity of the resulting solution, which is moles of solute per liter of solution

* First, we need to calculate the moles of iron(II) acetate. To do this we use the molar mass of iron(II) acetate:

Molar mass of Fe(C2H3O2)2 = 151.9 g/mol

* Then using the mass we were given and the molar mass, we can find the moles of iron(II) acetate using the formula:

moles = mass / molar mass

moles = 3.78 g / 151.9 g/mol

moles = 0.0249 moles of iron(II) acetate

* Next, the volume of the solution is 125 ml, which is 0.125 L (1 L = 1000 ml)

* So the molarity is calculated as:

Molarity = moles of solute / liters of solution

Molarity = 0.0249 moles / 0.125 L

Molarity = 0.199 M or 0.2 M (rounded to two significant figures)

So the molarity of iron(II) acetate in the resulting solution is 0.2 M.