A solution is made by completely dissolving 13.7 grams of potassium phosphate in 185.8 mL of water. What is the concentration of potassium in the solution?

In determining a concentration, we need to convert the result into Grams / Liter

We already have the correct conversion of the weight, now we just need to convert the water volume into Liter:

185.8 / 1000 = 0.1858 L

The concentration is:

weight / volume

= 13.7 gram / 0.1858 L

= 73.73 gram/liter