Question

your told to dissolve 0.5 moles of CuSO4 into water. How many grams is 0.5 moles of CuSO4

Answer 1

Explanation:

Molarity is simply a measure of how many moles of solute you have in one liter of a given solution. In order for a solution to have a molarity of

1 M

, it must contain

1

mole of solute for every

1 L

of solution.

In your case, you have a

0.5 M

solution of copper(II) sulfate,

CuSO

4

. This tells you that

1 L

of this solution contains

0.5

moles of copper(II) sulfate.

Since you have more than

1 L

of this solution, you are going to get more than

0.5

moles of solute. More specifically, you will get

5.1

L solution

⋅

0.5 moles CuSO

4

1

L solution

=

2.55 moles CuSO

4

Finally, use the molar mass of copper(II) sulfate to convert the number of moles to grams

2.55

moles CuSO

4

⋅

159.61 g

1

mole CuSO

4

=

410 g

−−−−−

I'll leave the answer rounded to two sig figs, but keep in mind that you only have one significant figure for the molarity of the solution.

Answer 2

Explanation:

The water of hydration would not significantly increase the number of ions, so there would be one mole of copper+2 and one mole of sulfate-2 in solution as this compound is soluble in water (assuming you had a liter or more of water to dissolve it in. So the answer is two moles of ions are in solution after dissolution is complete.