Chemistry Solutions and Concentration Review

Flashcards based on lecture notes focused on molarity, changes in concentration, and solubility.

How do you calculate molarity (M)?

Molarity is calculated using the formula M = moles of solute / liters of solution.

What is the molarity (M) of a solution containing 0.5 moles of NaCl dissolved in 2 liters of solution?

M = 0.5 moles / 2 L = 0.25 M.

Describe how to use the dilution formula M1V1 = M2V2 for dilution calculations.

In this formula, M1 and V1 represent the molarity and volume of the concentrated solution, while M2 and V2 represent the molarity and volume of the diluted solution.

Calculate the final volume (V2) needed to dilute 100 mL of a solution at 0.5 M to a final concentration of 0.1 M.

Using M1V1 = M2V2: (0.5 M)(100 mL) = (0.1 M)(V2); thus, V2 = (0.5 * 100) / 0.1 = 500 mL.

If a solution has a concentration of 0.2 M and you need 750 mL, how many moles of solute do you need?

Moles of solute = Molarity x Volume = 0.2 M x 0.750 L = 0.15 moles