An aqueous KNO₃ solution is made using 72.5 g of KNO₃ diluted to a total solution volume of 2.00 L. Calculate the molarity of the solution. (Assume a density of 1.05 g/mL for the solution.)

Key Concepts

Molarity

Molarity is a measure of concentration defined as the number of moles of solute per liter of solution. It is expressed in units of moles per liter (mol/L). To calculate molarity, one must first determine the number of moles of the solute, which can be found using the formula: moles = mass (g) / molar mass (g/mol).

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). For KNO3, the molar mass can be calculated by summing the atomic masses of potassium (K), nitrogen (N), and three oxygen (O) atoms. This value is essential for converting grams of KNO3 into moles, which is necessary for calculating molarity.

Solution Density

Density is defined as mass per unit volume and is crucial for converting between mass and volume in solutions. In this problem, the density of the KNO3 solution is given as 1.05 g/mL, which can be used to confirm the total mass of the solution if needed. However, for molarity calculations, the volume of the solution in liters is directly used, making density less critical in this specific context.