Also, we prepared 5% hydrochloric acid and 20% sodium hydroxide to be used for both qualitative and quantitative sections of the experiment. With the first test tube of magnesium, we added hydrochloric acid. The second test tube of magnesium we tested it with sodium hydroxide and the third test tube with magnesium was tested with mercury (II) chloride. We observed the reactions with magnesium first. After the magnesium, the same procedure was followed. Aluminum was tested with hydrochloric acid, sodium hydroxide, and mercury (II) chloride in separate test tubes. In addition, aluminum was also tested with nitric acid in another test tube. From these tests, we observed and confirmed which compound reacted best with which metal to proceed to the quantitative part of this experiment. Based on our results, magnesium reacted with hydrochloric acid as expected and mercury (II) chloride. Surprisingly though, aluminum reacted best with sodium hydroxide but not with mercury (II) chloride.
Quantitative.
To measure the amount of gas produced by magnesium, we placed 23mg of magnesium turnings in the Schlenk tube and connect it with rubber tubing to a container of water. Then we placed a burette of water upside-down into the water where the rubber tubing is connected to the Schlenk tube. When the apparatus was ready, we added 5% hydrochloric acid to the magnesium and collected the gas into the burette. We set up the exact same apparatus for the aluminum next to the magnesium to efficiently use our time while waiting for all the magnesium to react with the acid. In the apparatus with aluminum, we added 27mg of aluminum foil and 20% sodium hydroxide into another Schlenk tube and collected the gas produced from that. When both reactions stopped and no more gas could be collected, we measured the amount of gas collected in the burette and recorded it into our lab notebook.
III. Data, Calculations and Results.
