Testing the Stoichiometric Method (Jan. 28, 2010)

The purpose of our lab was to see if Stoichiometry accurately predicts the mass of products produced in chemical reactions.

The experimental design explains that 2.00 g of Strontium nitrate is dissolved in 50 mL of water and then reacted with excess Copper (II) sulphate (3.00 g). The product would be a precipitate (Strontium sulphate and Copper (II) nitrate) After mixing the solutions the precipitate would be seperated by filtration, dried and then weighed.

The balanced equation for this reaction is :
Sr (NO3)2 + CuSO4 ---> Sr SO4 + Cu(NO3)2

By calculating how many grams of Strontium sulphate should be produced after 2.00 g of Strontium nitrate is completely reacts, we came up with 1.74 g of SrSO4.

What to do? :

1. Carefully measure about 3.00 g of Copper (II) sulphate.
2. Dissolve the Copper (II) sulphate in 50 mL of water.
3. Carefully measure 2.00 g of Strontium nitrate and dissolve it in 50 mL of water.
4. Slowly pour the two solutions together.
5. Stir the mixture to complete the reaction
6. Write your group name on a piece of filter paper
7. Find and record the mass of the filter paper
8. Using a funnel and an Erlenmeyer flask, place the filter paper in the funnel and slowly pour the mixture into the funnel.
9. Pour the filtrate into the waste collection bottle
10. Finally, place the filter paper in the drying oven and record the mass when its dry.
    

Since the filter paper is still in the drying oven, we have not finished the lab, but will continue next class.