Question

Task:dilute 0.5 mol*dm^-3 CuSO4 . 5H2O into 250 ml water. Find the grams of CuSO4.5H2O

Answer 1

31.2 g of CuSO4.5H2O.

Step-by-step explanation:

What is given?

Molarity = 0.5 mol/dm³ (0.5 mol/L),

Volume = 250 mL = 0.25 L,

Molar mass of CuSO4.5H2O = 249.72 g/mol (you can calculate this amount using the periodic table).

Step-by-step solution:

Let's remember the concept of molarity: The molarity (M) of a solution is the number of moles of solute dissolved in one liter of solution. To calculate the molarity of a solution, divide the moles of solute by the volume of the solution expressed in liters:

`Molarity=\frac{numbe\text{r of moles}}{liters\text{ of solution}}.`

If we want to find the mass of CuSO4.5H2O in the solution, we have to find its number of moles, so let's clear for this value and replace the given data, like this:

`\begin{gathered} number\text{ of moles=Molarity}\cdot liters\text{ of solution,} \\ numbe\text{r of moles=0.5}(mol)/(L)\cdot0.25L=0.125\text{ moles.} \end{gathered}`

We have 0.125 moles of CuSO4.5H2O, and the final step is to find its mass using the given molar mass, like this:

`0.125\text{ moles CuSO}_4\cdot5H_2O\cdot\frac{249.72\text{ g CuSO}_4\cdot5H_2O}{1\text{ mol CuSO}_4\cdot5H_2O}=31.2\text{ g CuSO}_4\cdot5H_2O.`

The answer is that we have 31.2 g of CuSO4.5H2O in the solution.