Calculate the amount of solute needed to make the solution
.50kg of a 18% (m/m) KOH solution
To calculate the amount of solute needed to make a solution, you need to know the desired concentration of the solution and the mass or volume of the solution you want to prepare.
In this case, you want to prepare a 0.50 kg solution of 18% (m/m) KOH. The 18% (m/m) means that 18 grams of KOH is present in every 100 grams of the solution.
To find the amount of KOH needed, we can set up a proportion using the desired mass of the solution:
(18 g KOH / 100 g solution) = (x g KOH / 0.50 kg solution)
Now, let's solve for x, which represents the mass of KOH needed:
x g KOH = (18 g KOH / 100 g solution) * (0.50 kg solution)
x g KOH = (18/100) * 0.50 kg
x g KOH = 0.09 kg
Therefore, you would need 0.09 kg (or 90 grams) of KOH to make a 0.50 kg solution with a concentration of 18% (m/m).