DRAFT: This module has unpublished changes.

The purpose of this lab was to determine the identity of an unknown metal by reacting it with HCl. The three possible atomic weights for the unknown metal were approximately 61.15 g/mol, 105.95 g/mol, and 219.45 g/mol. By determining the atomic weight, we were able to determine the identity of that particular metal using the three stoichiometric ratios and the physical properties of the metal. The element with an atomic weight closest to 61.15 g/mol is copper. The problem is that copper has an oxidation number of 2+ and not 1+ so we must rule is out. The second possibility with an atomic weight of 105.95 g/mol was palladium. This was more concise with our predictions because palladium has an oxidation number of 2+ or 4+ so this might very well be our metal. The third possibility with an atomic weight of 219.45 g/mol was francium; however, the oxidation number of francium is 1+ and not 3+ as expected so we must rule this option out. This only leaves us with one option for the mystery metal which is Pd2+(palladium). The reaction occurred in the following chemical formula and palladium (II) chloride was the product along with the hydrogen gas.

 

Pd2+(s) + HCl(l) ------->PdCl2+H2

 

Possible errors could have come from not covering the flask fast enough in order to contain the hydrogen gas because the reaction occurred very quickly. Another error could have come from not submerging the flask enough in the water or the rubber stopper not forming an airtight seal, allowing some hydrogen gas to escape. Other errors could have been caused by the data collection system not being set up properly or not reading the data correctly.

DRAFT: This module has unpublished changes.