The objective of this lab was to calculate the ratio of the copper sulfur compound to conclude whether the compound is made of copper I or II.
A copper coil was twisted.
The mass of the copper coil was found.
The copper coil was placed in a crucible.
A sulfer powder was added to the crucible to cover the copper coil.
The cover was placed on the crucible.
The Bunsen burner was lit.
The covered crucible was placed on the triangle, on the ring stand, above the flame.
The crucible was heated for about 10 minutes or until all the powder is gone.
The crucible is allowed to cool.
The coil is massed.
Mass of Sulfide = mass of compound - mass of copper coil
Emperical ~ mass of copper coil x ___1 mole___ = ___moles Cu
Gram molar mass Cu
Mass of Sulfide x ___1 mole___ = ___ moles S
Gram molar mass S
Emperical Ratio: __moles Cu / ___moles S : __ moles S / __moles S
% Composition ~ _mass of element_ x 100
mass of compound
mass : mass conversion ~
mass of Cu x _1 mole Cu_ x 1 mole compound x gram molar mass of compound = mass
gram molar mass Cu gram molar mass S 1 mole of compound of compound
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Copper II Sulfide ~ (final mass of compound) _ç3.07g - 2.59gç_ x 100 = 15.6%
The compound was predicted to be Copper I Sulfide because the error analysis of the final mass was only 1.17% and the error analysis of Copper II Sulfide was 15.6%. Also the empirical ratio is 2:1 which fits Copper I Sulfide (Cu2S), but not Copper II Sulfide which has an empirical ratio of 1:1. The % composition and mass : mass conversion was calculated for both Copper I Sulfide and Copper II Sulfide in order to make sure the results and conclusions were as accurate as possible.
There were no problems during lab. The process ran smoothly. To improve this lab, the cover should not be removed from the crucible until the powder has completely disappeared.