Precipitate Lab

Data Collection

Qualitative for reacting Strontium Chloride with water and Copper (II) Sulphate:

• Water goes a light blue, like the copper powder
• Crystals have expanded, they look fluffy, forming precipitate, blueish in colour

Qualitative results when filtering:

• Precipitate is white with blue
• Then went a green colour
• Water is very blue
• Precipitate got gooopy

Quantitative:

• 2g strontium chloride
• 2g copper (II) sulphate
• 75 ml water
• Mass precipitate 0.522 g

Sr(Cl)2 + CuSO4 --> SrSO4 + Cu(Cl)2

SrSO4 precipitates in white crystals;
Cu(Cl)2 stays dissolved in water forming a bluish solution.

m Sr (Cl)2= 2.015 g

M Sr (Cl)2= 158.526 g/mol

m CuCl2=2.035 g

M CuCl2= 159.611 g/mol

n Sr(Cl)2= 2.015 g / 158.526 g/mol

            =0.0127108 mol

             =0.0127 mol

n CuCl2= 2.035 g / 159.611 g/mol

           =0.0127497 mol

               =0.0128 mol

Mole ratio is 1:1 for this reaction, there was 0.0127123 moles of Strontium Chloride, you would need 0.0127 moles of Copper (II) Sulphate, but since there was0.0127498 moles of the Copper, (slightly more than the number of Strontium Chloride) means the Strontium Chloride is the limiting factor in this reaction.

Seeing as the Strontium Chloride is the limiting factor for this reaction:

n Sr(Cl)2= 0.0128 mol  (1:1)

M SrSO4= 183.685 g/mol

m= 0.0128 mol x 183.685 g/mol

   = 2.335058826 g SrSO4 produced

  =2 g SrSO4 produced

The amount of precipitate had left in our experiment was 0.522 g, which was quite far away form the theoretical mass of 2.335 g.

Conclusion

Therefore, the actual mass of the precipitate left in this experiment was 0.522 g, which was in turn quite distant from the theoretical mass of 2.335 g.     

Evaluation