Titration
Experiment #10
Volumetric Analysis
The Titration of Acids and Bases
Purpose
This experiment will allow you to gain practical experience in the preparing standard solutions, using a pipette and a buret, and performing standard titrations. You will use this experience to experimentally determine the concentration of acetic acid in an unknown solution. There are three parts to this experiment, they are 1. Preparation a standard solution of oxalic acid (~0.07 M) 2. Preparation a sodium hydroxide solution (~0.1M) which will be standardized using the standard oxalic acid solution. 3. Determination of the concentration of acetic acid in an unknown vinegar solution. (0.1-0.2M)
Introduction
Standard solutions are solutions with known concentrations, generally to four significant figures. There are two different ways to make a standard solution. We can make a primary or a secondary standard. A primary standard is prepared directly by dissolving a known mass of sample to make a known volume of solution. A secondary standard is prepared by dissolving an approximate amount of sample into a volume of solvent and determining its exact concentration through titration experiments. Primary standards are prepared from compounds that are at least 99.9% pure, have a definite composition, are water soluble, are easily weighed, and do not change composition on contact with air. Oxalic acid dihydrate (H2C2O4•2H2O) fits these criteria and therefore may be used as a primary standard. Sodium hydroxide absorbs water when it comes into contact with air and therefore it is difficult to obtain a pure, dry sample to weigh. For this reason the sodium hydroxide solution will be titrated with the oxalic acid standard to become a secondary standard.
In the first part of this experiment you will prepare a solution of known concentration of oxalic acid. The oxalic acid crystallizes with two water molecules per oxalic acid in the crystalline network. For this
Volumetric Analysis
The Titration of Acids and Bases
Purpose
This experiment will allow you to gain practical experience in the preparing standard solutions, using a pipette and a buret, and performing standard titrations. You will use this experience to experimentally determine the concentration of acetic acid in an unknown solution. There are three parts to this experiment, they are 1. Preparation a standard solution of oxalic acid (~0.07 M) 2. Preparation a sodium hydroxide solution (~0.1M) which will be standardized using the standard oxalic acid solution. 3. Determination of the concentration of acetic acid in an unknown vinegar solution. (0.1-0.2M)
Introduction
Standard solutions are solutions with known concentrations, generally to four significant figures. There are two different ways to make a standard solution. We can make a primary or a secondary standard. A primary standard is prepared directly by dissolving a known mass of sample to make a known volume of solution. A secondary standard is prepared by dissolving an approximate amount of sample into a volume of solvent and determining its exact concentration through titration experiments. Primary standards are prepared from compounds that are at least 99.9% pure, have a definite composition, are water soluble, are easily weighed, and do not change composition on contact with air. Oxalic acid dihydrate (H2C2O4•2H2O) fits these criteria and therefore may be used as a primary standard. Sodium hydroxide absorbs water when it comes into contact with air and therefore it is difficult to obtain a pure, dry sample to weigh. For this reason the sodium hydroxide solution will be titrated with the oxalic acid standard to become a secondary standard.
In the first part of this experiment you will prepare a solution of known concentration of oxalic acid. The oxalic acid crystallizes with two water molecules per oxalic acid in the crystalline network. For this