STANDARDIZATION AND TITRATION OF SOLUTIONS

Learning Objectives

Upon completion of this experiment, students should be able to:

1. 1. (CLO1). Explain basic chemical concepts related to chemical changes, energy, and properties of matter.

   2. (CLO4). Interpret and utilize mathematical formulas while solving problems

   3. (CHM 111 MLO7) Calculate the molarity of a solution using molar mass and the mole concept: convert between mass, moles, and molarity utilizing titration techniques

   4. (CHM 111 MLO7) Determine the concentration of a solution that has been diluted in addition to applying dilution principles toward serial dilutions.

   5. (MLO2) Calculate solution concentration or interchange concentration units of molarity, molality, Percent and mole fractions.

   6. Determine the concentration of a bleach solution through titration with a standardized sodium thiosulfate solution in an Iodometric reaction in quantitative analysis.

Discussion

Stoichiometry is the quantitative determination of a substance through the use of a chemical reaction and the molar ratios. In this experiment, we will titrate a solution containing a primary standard to determine the molarity of a sodium thiosulfate solution. Titration techniques are often utilized to determine the stoichiometry of a reaction and the concentration of unknown solutions. Many compounds used for titration, such as sodium hydroxide are either too impure or too hygroscopic to be weighed accurately. In order to find the concentration of a sodium hydroxide solution accurately, it is necessary to titrate it against a primary standard. Primary standards are compounds that are certified to be at least 99.9% pure and are not hygroscopic. Sodium thiosulfate is not a primary standard so in order to determine the concentration of a sodium thiosulfate solution accurately; it must be titrated against one of several primary standards. In the procedure below, potassium ferricyanide is used because of its relatively high equivalent mass.

The standardized solution of sodium thiosulfate is used to determine the concentration of a bleach solution.

Tyler DeWitt: Oxidation Reduction (Redox)

• • • Introduction to Oxidation Reduction (Redox) Reactions

    • The Oxidation Reduction Question that Tricks Everyone!

    • How to Calculate Oxidation Numbers Introduction

    • How to Calculate Oxidation Number Practice Problems

    • Oxidizing Agents and Reducing Agents

    • How to Balance Redox Equations in Acidic Solution

    • How to Balance Redox Equations in Acidic Solution Example 1

    • Balance Redox Equations in Acid Example 2 (Advanced)

    • How to Balance Redox Equations in Basic Solution

    • Balancing Redox Equations in Basic Solution Example Problem