We need to use the formula of mass percent, which is:
[tex]\text{mass percent=}\frac{mass\text{ of solute}}{mass\text{ of solution}}\cdot100,[/tex]Our solute is 114 g of KCl and the solution is the sum of the solute and solvent (water). We replace these amounts on the formula:
[tex]\text{mass percent=}\frac{114}{114+598}\cdot100=16.01;[/tex]So, the concentration of 114g of KCl in 598g of water is 16.01%