Hoeveel gram opgeloste stof moet je afwegen om 250 ml KMnO4-oplossing te bereiden met een concentratie van 0,500 mol / L

How many grams of solute do you have to weigh to prepare 250 ml KMnO4 solution with a concentration of 0.500 mol / L

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

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Explanation:

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.