Mole mass lab

Mr. O
Lab 14
Mass-Mass Relationships in Reactions
Equipment: balance, 100 mL graduated cylinder, 250 and 100 mL beaker, stirring rod, ring stand, iron ring,
and funnel
Materials: zinc acetate [Zn(C2H3O2)2 + 2H2O], sodium tribasic hydrate(Na3PO4 + 12 H2O), and filter paper
Observation and Data:
a. Mass of Zn(C2H3O2)2 + 2H2O _________g
b. Mass of filter paper _________g
c. Mass of filter paper and precipitate _______g
d. Observations
1. Balance the following equation
__Na3PO4 + 12 H2O + ___Zn(C2H3O2)2 + 2H2O  __Zn(PO4)2 + 4H2O + ___NaC2H3O2 + ___H2O
2. Using the mass-mass calculations, find the theoretical mass of Zn(PO4)2 + 4H2O precipitate that should be
produced from 2.19g of Zn(C2H3O2)2 + 2H2O reacts completely.
3. Find the experimental mass of Zn(PO4)2 + 4H2O formed (c-b)
4. Find the experimental error.
Conclusion and Questions:
1. What type of reaction was the experiment?
2. Why does this reaction go to completion and is not reversible?
3. Suggest some possible errors in this experiment.
4. Define the terms filtrate and precipitate.
5. How would of the results changed if the precipitate were not completely dry?
6. Why is it important to rinse the precipitate several times?