Question

How much KMnO4 is needed to prepare 250mL of 2.5*10^-3 M KMnO4 solution?

Answer 1

Number of moles=Concentration(mol/dm^3)*Volume(dm^3)
convert volume units from cubic decimeter to milliliter
1 dm3 = 1000 ml
x dm^3=250 ml
Cross multiplication to find x (volume) but in dm^3 instead of ml
250*1/1000*2.5*10^-3=Number of moles of KMnO4

Answer 2

Why dm^3 instead of L?

Answer 3

its the same

Answer 4

Let me do the work and see if I got it right.
\[250mL*\frac{ 1L}{ 1000mL } = .25L\]
\[.25L*\frac{ 2.5*10^{-3}mols }{ L }= 6.25*10^{-4}\]
\[6.25*10^{-4}mols*\frac{ 158.032g KMnO4 }{ 1 mol KMnO4 }= .09877g\]
Is this right?

Answer 5

good job :)

Answer 6

Thanks for the help