Question

How would you prepare 2.18 L of a 4.00 M solution from a 16.0 M stock solution

Answer 1

given

16 M stock solution

we need to make 2.18 L of 4 M solution

now

we know that

moles = molarity x volume (L)

so

moles required = 4 x 2.18

moles required = 8.72

now

we need to get 8.72 moles from stock solution

so

we know that

molarity = moles / volume (L)

so

16 = 8.72 / volume (L)

volume (L) = 0.545

so

0.545 L of stock solution is required

water added = final volume - initial volume

water added = 2.18 - 0.515

water added = 1.635

so

1.635 L of water is needed

now

the steps are

1) take 0.545 L of 16 M stock solution

2) add water to make the final volume to 2.18 L

simply for dilution

M1V1 = M2V2

16x V1 = 4 x 2.18

V1 = 0.545

so

0.545 L of stock solution