how do you make a 50 mL 2% KMnO4 solution? YOu know, the steps and the chemicals needed?

Question

please..i need help...THANK YOU!

Answer 1

2% KMnO4 means 2 g KMnO4 in 100 mL of solution.
For 50 mL, you need half, thus 1 g KMnO4.

Procedure:
Take a 50 mL volumetric flask or an appropriate volumetric cylinder (50 or 100 mL cylinder). Put some water (e.g. 30-40 mL) dissolve the KMnO4, add water up to 50 mL, mix so that it is homogeneous and you're done. This is the proper way to prepare solutions and not as Maurizia described. Only when you are dealing with volumes <2 mL you do the approximation Vtotal=Vsolvent+Vsolute when the solute is actually liquid or a concentrated solution or Vtotal=Vsolvent if the solute is a solid

Answer 2

Per cent by volume is definined as the percent of the final volume that is rapresented by the initial volume of the component in question.
2%= 2/100 .100
So we have to put 1g of KMnO4 in enought water to make 50 mL of solution
Per cent by weight 1g of KMnO4 in 49 g of H2O