Understanding Mass Percent and Molarity in Solution Composition
This document explores the concepts of mass percent and molarity in solution composition. It details how to calculate the mass percent of a solute, using the example of 13.4g of NaCl dissolved in 56.6mL of water. The document also explains molarity as the number of moles of solute per liter of solution, with examples such as 6 moles of sugar in various solution volumes. Additionally, it addresses practice problems for calculating molarity and the preparation of standard solutions using volumetric flasks.
Understanding Mass Percent and Molarity in Solution Composition
E N D
Presentation Transcript
Describing Solution Composition 15.2: Pgs 528 - 534
Mass Percent • Describes the amount of solution in terms of mass • Suppose a solution is made by dissolving 13.4g of NaCl in 56.6 mL of water. What is the mass percent of NaCl in this solution?
Solution Concentration • Molarity: number of moles of solute per liters of solution • Molarity
Solution Concentration • Molarity – What is the molarity of a 1 L solution containing 6 moles of sugar? What is the molarity if the 6 moles of sugar is dissolved in only 500 mL of solution?
Example: • What is the molarity if 11.5 g of NaOH is added to 1.5 L of water?
Practice!! • What is the molarity if 1.56 g of HCl is added to 26.8 mL of solution.
Practice 2!! • How many grams of formaldehyde (HCHO) must be used to prepare 2.5 L of 12.3 M solution?
Solution Concentration • Standard Solution – when the concentration is accurately known. • Made using a volumetric flask
