Concentration

Objective: Calculate concentration with clearly stated units.

Concentration compares an amount of solute to a specified amount of solution or solvent. Mass concentration may be expressed as grams of solute per liter of solution; for 10 g dissolved to make 2.0 L total solution, it is 5.0 g/L. Mass percent equals solute mass divided by total solution mass times 100; 5 g solute in 100 g solution is 5%. Molarity is moles of solute per liter of solution, and requires converting mass to moles if mass is given. Always distinguish final solution volume from starting solvent volume and include units. A concentrated solution has more solute per specified amount than a dilute one, without implying saturation.

Objective: Apply concentration to calculations, evidence, and specified situations.

Molarity is solute amount divided by total solution volume in liters. The denominator is final solution volume, not merely solvent volume. For dilution without reaction or solute loss, M1V1=M2V2 because moles of solute are conserved. Use compatible volume units and distinguish a dilution from adding more solute. Temperature can affect volume and therefore molarity; these exercises treat volumes as specified under the same conditions.