Chem 1211K Lab Report
Chemistry 1211K Lab Report
Briana Limage
Drawer #D20
Tuesday December 2, 2014
Lab Day and Time: Tuesday 2-5
Unknown # 4224034-DF14
Introduction
The purpose of this semester long experiment was to determine an unknown organic acid. An organic acid is an organic compound with acidic properties. A base reacts with acids to form salts. Titrations are used to determine the concentration of unknown substances. The purpose of the KHP experiment was to determine the molarity of NaOH. HCl titrations are mainly to check technique and used to verify the molarity of NaOH solution. The hypothesis is that this acid is C4H3OCOOH.
Experimental
Procedure for melting point:
The identification of the melting point of the organic acid was done to find another characteristic of the acid and to test the purity of the recrystallized pure acid. A 2-4 mm layer of unknown sample was placed into a capillary tube sealed on one end. Then the capillary tube was inserted into the side a Bibby Sterlin device. The plateau was set to 200°C on the melting point apparatus. Once the plateau temperature was reached, the sample was watched carefully. When the sample first began to melt and when it was fully melted was recorded. These numbers were the range of the melting point. A slow melting point of the unknown organic acid and a standard sample was completed next. A new plateau was set about 10°C lower than the observed melting point of the unknown sample. This time once the plateau was reached, the heating was no more than 1°C per minute. This gave a much more accurate read of both melting points. If the standard did not melt in the range listed on the label of the bottle, that meant the machine was not working properly. The standard sample and the unknown organic acid melted in their appropriate ranges.
Procedure for equivalent weight: A sodium hydroxide solution was prepared. Then 4.2 mL of concentrated 19.1 M NaOH was obtained and mixed with 800 mL dH2O in a 1L bottle.
Briana Limage
Drawer #D20
Tuesday December 2, 2014
Lab Day and Time: Tuesday 2-5
Unknown # 4224034-DF14
Introduction
The purpose of this semester long experiment was to determine an unknown organic acid. An organic acid is an organic compound with acidic properties. A base reacts with acids to form salts. Titrations are used to determine the concentration of unknown substances. The purpose of the KHP experiment was to determine the molarity of NaOH. HCl titrations are mainly to check technique and used to verify the molarity of NaOH solution. The hypothesis is that this acid is C4H3OCOOH.
Experimental
Procedure for melting point:
The identification of the melting point of the organic acid was done to find another characteristic of the acid and to test the purity of the recrystallized pure acid. A 2-4 mm layer of unknown sample was placed into a capillary tube sealed on one end. Then the capillary tube was inserted into the side a Bibby Sterlin device. The plateau was set to 200°C on the melting point apparatus. Once the plateau temperature was reached, the sample was watched carefully. When the sample first began to melt and when it was fully melted was recorded. These numbers were the range of the melting point. A slow melting point of the unknown organic acid and a standard sample was completed next. A new plateau was set about 10°C lower than the observed melting point of the unknown sample. This time once the plateau was reached, the heating was no more than 1°C per minute. This gave a much more accurate read of both melting points. If the standard did not melt in the range listed on the label of the bottle, that meant the machine was not working properly. The standard sample and the unknown organic acid melted in their appropriate ranges.
Procedure for equivalent weight: A sodium hydroxide solution was prepared. Then 4.2 mL of concentrated 19.1 M NaOH was obtained and mixed with 800 mL dH2O in a 1L bottle.