How many grams of solute do you have to weigh to prepare 250 ml KMnO4 solution with a concentration of 0.500 mol / L
Answer:
19.75g
Explanation:
Given parameters:
Volume of KMnO₄ = 250mL or 0.25L
Concentration of solution = 0.5mol/L
Unknown:
Mass of solute or KMnO₄ = ?
Solution:
To solve this problem, we need to find the number of moles first.
Number of moles = Concentration x volume
Number of moles = 0.5mol/L x 0.25L = 0.125mol
So;
Mass in grams = number of moles x molar mass
Molar mass of KMnO₄ = 39 + 55 + 4(16) = 158g/mol
Mass in grams = 0.125 x 158 = 19.75g