Qualitative Analysis In Chemistry

Identifying features and key components of unknown chemical mixtures are an essential part of chemistry. In many cases it is necessary to analyses and understand the chemical makeup of pharmaceuticals. Qualitative analysis is a method of testing a chemical mixture to determine its chemical makeup, such as its functional group. Identifying functional groups of an unknown compound are important, as it helps in understanding how a chemical acts under certain conditions, such as when changing physical states. Depending on the functional group, the boiling point will be higher or lower, due to the strong or weak intermolecular forces. In this experiment qualitative analysis is used to identify two unknown samples, a liquid and a solid (L21 and

Classification Test:

Jones Test:

One drop of the liquid (L21) was placed in a test tube. But for the solid unknown (S21) 5mg was added to the test tube. 0.5mL of acetone was added with 1 drop of jones reagent. The results were recorded. The test tubes were then discarded in the hazardous waste container.

TCICA:

0.5mL of TICICA in acetonitrile, 1 drop of 1M HCL, and 1 drop of unknown liquid (L21) or 10mg of solid unknown (S21) was added to a test tube. A timer was set up and started after the solutions were mixed together in the test tube. Then the test tube was flicked several times and then placed in a test tube rack holder. The reaction stopped when a precipitate formed. The speed of the reaction was recorded and the results of the test were identified. The NaHSO_3 and water were added to the test tubes and disposed of in the waste container. Iodoform:

Four drops of the unknown liquid (L21) or 50mg of solid unknown (S21) is mixed with 2mL of water in a test tube. 2mL of 3M sodium Hydroxide was then added. 3mL of iodine solution was added. The results of the reaction were

Since it is a primary alcohol, this confirms the conjecture that was made. Looking at the H-NMR, it is obvious that there are four types of hydrogen. One type is at 3.65ppm which is the OH bond. The second type at 1.6ppm is the CH2 next to the OH bond, because the splitting at 3.65ppm is 2, meaning it is next to a CH2. The third type is at 1.3ppm which indicates the rest of the CH2’s in the chain. Lastly the fourth type is at 0.9ppm, indicating a CH3 at the end of the structure. The splitting is 2, which means it is next to a CH2. Just looking at the H-NMR, this supports that the unknown is 1-octadecanol. Looking at the C-NMR next, there are many carbon peaks. The 63ppm identifies the CO bond. The peak at 17ppm identifies the CH3 at the end of the chain. The rest of the peaks fall within the CH2 range, this proves the rest of the carbons in the