Question

How many mL of 0.650 M solution can be prepared by dissolving 15.0 g of copper(II) nitrate in

water?

Answer 1

123.1L

Step-by-step explanation:

Given parameters:

Molarity of Cu(NO₃)₂ = 0.650M

Mass of Cu(NO₃)₂ = 15g

Unknown:

Volume of Cu(NO₃)₂ = ?

Solution:

To solve this problem, we have to first find the number of moles of the given mass;

Number of moles of Cu(NO₃)₂ =
`(mass)/(molar mass)`

Molar mass of Cu(NO₃)₂ = 63.5 + 2 (14 + 3(16)) = 187.5g/mol

Number of moles of Cu(NO₃)₂ =
`(15)/(187.5)` = 0.08 mol

Molarity is given as;

Molarity =
`(number of moles )/(volume)`

Volume =
`(number of moles )/(molarity )`

Insert the parameters and solve;

Volume =
`(0.08)/(0.65)` = 0.12L

Now mL;

1L = 1000mL

0.12L will give 1000 x 0.12 = 123.1L