Question

How many grams of CuSO4 must be dissolved in 100 mL of total solution to create a 0.25 M solution of CuSO4?

A) 4 g

B) 25 g

C) 40 g

D) 159 g

Answer 1

Answer:

A) 4 g

Explanation:

Data:

V  =100 mL = 0.1 L

M  = 0.25M

g = ?

Molarity

$M=\frac{mol}{volume}$

The moles are cleared from this equation:

$mol=M*V=0.25M*0.1L=0.025mol CuSO_{4}$

Through the molecular weight, the grams of CuSO4 are calculated, knowing that the molecular weight of CuSO4 is 160 g/mol.

$MW=\frac{mol}{mass}$

$mass=MW*mol=160\frac{g}{mol} *0.025mol=4 g CuSO_{4}$