Chem lab module 7 - Essay Example

The solution and the solid were separated by decantation. I divided the remaining solid available to perform vinegar. Since no bubbles were seen, the possible compounds were narrowed down to Plaster of Paris and cream of tartar. On addition of hydrochloric acid, the precipitate didn’t dissolve, thereby, confirming the solid precipitate to be Plaster of Paris. Moving to the solution part, a violet color was obtained on carrying out the pH test, which narrowed down the compounds to table salt, glucose and sucrose.

On copper sulphate test, no reddish brown precipitate was observed; hence presence of glucose was not possible. The only other sugar that could be present otherwise was sucrose. I took 2g of the given unknown mixture in a test tube and added water. After decanting the solution from the solid, I carried out the identification tests separately on the solid and the solution parts. I, first, carried out the iodine test on the solid precipitate and got a negative result. Next I performed the vinegar test and observed bubbles rise from the test tube, hence confirming the presence of baking soda.

In the remaining solid part, which I had previously separated into another test tube, I added hydrochloric acid. Since the precipitate didn’t dissolve, the other constituent of the mixture was identified as Plaster of Paris. I added 2g of mixture 2 in a test tube followed by 10 ml of water. After separating the solution from the solid, I performed the pH test on the solution and obtained green color. To distinguish between the possible presence of drain opener and washing soda, I added vinegar, after taking 2ml of the solution in another clean test tube.

Bubbles were seen to rise in the tube, hence confirming the presence of drain opener. In the solid part, I performed the iodine test, followed by vinegar test only to be met by a negative result. The possible compounds were narrowed