9.25% KCl solution is prepared by dissolving enough of the salt to give 100.0 g of solution. What is the mass of water required?
% w/w = [(mass solute)/(total mass soln)]*100 = ?
mass soln is mass solute + mass solvent. If the total is 100 g and mass solute is 9.25 g, what is mass solvent.
To find the mass of water required, we need to calculate the mass of the KCl salt in the solution.
Step 1: Convert the percentage concentration to a decimal by dividing it by 100:
9.25% = 9.25/100 = 0.0925.
Step 2: Calculate the mass of KCl in the solution by multiplying the percentage concentration by the total mass of the solution:
Mass of KCl = 0.0925 x 100.0 g = 9.25 g.
Step 3: Since the mass of the solution is equal to the mass of KCl + mass of water, we can subtract the mass of KCl from the total mass of the solution to find the mass of water:
Mass of water = Total mass of solution - Mass of KCl = 100.0 g - 9.25 g = 90.75 g.
Therefore, the mass of water required to prepare the 9.25% KCl solution is 90.75 grams.