How many grams of kmno4 are required to prepare 2.000 l of . 04000m kmno4 solutin that is used in titrating na2c2o4?

Molarity is defined as the number of moles of solute in a volume of 1 L solution. 
the KMnO₄ solution to be prepared should have a molarity of 0.04000 M
the volume of solution to be prepared is - 2.000 L
the number of KMnO₄ moles required - 0.04000 mol/L x 2.000 L = 0.08000 mol
molar mass - 158 g/mol 
The mass of KMnO₄ required to make the solution - 158 g/mol x 0.08000 mol 
mass of KMnO₄ required - 12.64 g

What’s the solution?