Question

Solution calculations.a student needs to make a 900 ml of a 0.75 M solution of cuso4 what mass in grams of solute is needed to make a solution]

Answer 1

Answer: Mass of solute needed = 107.74 grams of CuSO4

Explanation

GIVEN

• Volume ,=, 900 ml = 900/10,00 = 0.9L

,

• Concentration, = 0.75 M = 0.75 mol/L

,

• Molar mass CuSO4, = 159,609 g/mol

(i) Calculate moles of CuSO4

`\begin{gathered} Concentration\text{ = }\frac{Moles\text{ }}{Volume\text{ }} \\ \therefore Moles\text{ = Volume * Concentration } \\ \text{ = 0.9 L * 0.75 mol/L } \\ \text{ Moles =0.675 moles of CuSO}_4 \end{gathered}`

Therefore , Moles CuSO4 = 0.675

(ii) Calculate Mass of CuSO4

`\begin{gathered} Moles\text{ CuSO}_4=\text{ }\frac{Mass\text{ CuSO}_4}{Molar\text{ mass CuSO}_4} \\ \therefore Mass\text{ CuSO}_{4\text{ }}=\text{ Moles CuSO}_{4\text{ }}*\text{ Molar mass CuSO}_4 \\ \text{ =0.675 moles * 159.609g/mol} \\ \text{ = 107.74 grams } \end{gathered}`

Therefore; Mass of solute needed = 107.74 grams of CuSO4