In a solution, the solute is distributed evenly throughout the solvent.
This ratio is the concentration of the solution.
Concentration = amount of solute in solution
Molarity (M) is expressed as moles of solute per liter of solution.
Molarity describes concentration in terms of volume of solution , not volume of solvent.
If you simply added 1.000 mol solute to 1.000 L solvent, the solution would not be 1.000 M.
The added solute will change the volume, so the solution would not have a concentration of 1.000 M.
M = Molarity n = moles You need these three variables in every problem. L = Liters M = n/L n = ML L = n/M Does the question give you grams? Convert grams to moles (n). Find molar mass of the compound. Divide grams given by molar mass to get moles (n). Does the question give you mL? Convert to Liters. Move the decimal three places to the left. DO NOT ROUND UNTIL THE END. Round everything to the 100th. Ex: 45 = 45.00, 65.432 = 65.43, 8.767 = 8.77 Don’t forget to LABEL.
Calculating Molarity Sample Problem What is the molarity of a potassium chloride solution that has a volume of 400.0 mL and contains 85.0 g KCl?
Sample Problem Solution volume of solution = 400.0 mL mass of solute = 85.0 g KCl molarity of KCl solution = ?
Look through the section for examples. You will need your periodic table and maybe mole island.