Practice Concentration in Chemistry
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
The quantity of solute dissolved per unit volume of solution, most commonly expressed as molarity (M) in units of moles per liter (mol/L). Concentration quantifies how much solute is present relative to the total solution volume.
How 'strong' a solution is—more solute in the same volume = more concentrated.
Example 1
easyCalculate the molarity of a solution made by dissolving 5.85 g of NaCl in water to make 500\,\text{mL} of solution. (NaCl molar mass = 58.44\,\text{g/mol})
Example 2
mediumHow many grams of KOH are needed to prepare 250\,\text{mL} of a 0.40\,\text{M} solution? (KOH = 56.11\,\text{g/mol})
Example 3
mediumCalculate the molarity of a solution made by dissolving 5.85 g of NaCl (molar mass 58.5 g/mol) in enough water to make 500 mL.
Example 4
easyWhat is the molarity of a solution containing 0.50 mol of solute in 2.0 L?
Example 5
easyWhat is the molarity of a solution made by dissolving 0.750 mol of \text{KNO}_3 in enough water to make 2.50 L of solution?