Answer:
To prepare 250 ml of 0.15 M KNO3 solution, you will need to follow these steps:
Calculate the amount of KNO3 needed:
Molarity (M) = moles of solute/liters of solution
Rearranging the formula, moles of solute = M x liters of solution
Moles of KNO3 needed = 0.15 M x 0.25 L = 0.0375 moles
Calculate the mass of KNO3 needed:
Mass = moles x molar mass
The molar mass of KNO3 is 101.1 g/mol
Mass of KNO3 needed = 0.0375 moles x 101.1 g/mol = 3.79 g
Dissolve the calculated amount of KNO3 in distilled water:
Weigh out 3.79 g of KNO3 using a digital balance
Add the KNO3 to a clean and dry 250 ml volumetric flask
Add distilled water to the flask until the volume reaches the 250 ml mark
Cap the flask and shake it well to ensure the KNO3 is completely dissolved
Verify the concentration of the solution:
Use a calibrated pH meter or a spectrophotometer to measure the concentration of the solution
Adjust the volume of distilled water or the mass of KNO3 as needed to achieve the desired concentration
It is important to note that KNO3 is a salt that can be hazardous if ingested or inhaled in large quantities. Therefore, it is recommended to handle it with care and wear appropriate personal protective equipment.
Step-by-step explanation: