Discussion/Conclusion:

The purpose of this lab is to determine how a reaction between an unknown metal and an acid can be used to identify the metal and this task was completed successfully. Our lab group determined unknown metal one to be magnesium.

HCl was reacted with an unknown metal in a flask submerged in a water bath. The unknown metal reacted with HCl and hydrogen gas was released in a closed container with a known volume and known temperature. The pressure, volume, and temperature were recorded which allowed us to find the number of moles of the hydrogen released using the ideal gas law. Using the recorded mass of unknown metal one, the moles of hydrogen gas released, and the given stoichiometric ratios, we calculated three possible atomic weights. The 2:1 ratio possibility of 12.94 g/mol gave the possibility of carbon or nitrogen. This could be eliminated because both elements are not metals. The 2:3 ration possibility of 38.83 g/mol gave the possibility of chlorine or argon. Again, both of these elements are not metals and could be eliminated. Lastly, the second possibility ratio of 1:1 and 25.88 g/mol gave the possibility of the metal to be magnesium or aluminum. Because magnesium is a metal and has an atomic weight closer to this value, we concluded the unknown to be magnesium. This result makes sense because magnesium reacts quickly with HCl and in the reactions also produces hydrogen gas.

This lab was an example of how to identify and unknown metal. Although the process was very short, it was difficult because the reaction between the magnesium and HCl happens so quickly. For this reason, there are a few sources for error in this experiment.  Some of these include measuring the HCl inaccurately, not putting on the rubber stopper fast enough leading to the release of hydrogen gas into the air, and not having the rubber stopper tight enough. To improve the results in future labs, it would be important to find another way of securing the rubber stopper other than having a member hold it in place.