Question

Select the correct answer from each drop-down menu. To prepare a 2 M solution of potassium nitrate (KNO3), which quantities must be measured? The mass of the and the volume of the must be measured.

Answer 1

To prepare a 2 M solution of potassium nitrate, you must measure the mass of potassium nitrate and the volume of water, using the compound's molar mass to calculate the correct mass for the desired concentration and volume.

Step-by-step explanation:

To prepare a 2 M solution of potassium nitrate (KNO3), which quantities must be measured? The answer is: The mass of the potassium nitrate and the volume of the water must be measured. In making solutions, molarity (concentration) is defined as the number of moles of solute per liter of solution. Therefore, to prepare a 2 M solution, one needs to dissolve an amount of solute that will provide 2 moles of KNO3 for every liter of solution.

First, you will need to calculate the mass of KNO3 required by using its molar mass. After that, measure this mass using a balance. The volume of water is similarly important because it will determine the final volume of the solution, which should be measured with a graduated cylinder or volumetric flask. For example, if you need to prepare 1 L of a 2 M solution, you would dissolve the calculated mass of KNO3 in enough water to make the total volume 1 L.