Final answer:
The molarity of the KNO₃ solution is 2.00 M.
Step-by-step explanation:
To calculate the molarity of a solution, you need to know the amount of solute in moles and the volume of the solution. In this case, the given mass of KNO₃ is 404 grams and its molecular mass is 101 g/mol. To find the number of moles, divide the given mass by the molecular mass: 404 g / 101 g/mol = 4 moles. The volume of the solution is 2.00 liters. Finally, divide the number of moles by the volume to calculate the molarity: 4 moles / 2.00 L = 2.00 M.