Chem: Lab Report: Mole-mass Relationships In Reactions u2v6x

LAB REPORT MOLE-MASS RELATIONSHIPS IN REACTIONS

PURPOSE To compare the theoretical mass of one of the products of a double replacement reaction with the experimentally determined mass of the same product.

DATA & CALCULATIONS DATA COLLECTED Variable mass of mass of filter paper mass of filter paper & precipitate observations of the reaction between

Value 2.19 g 0.71 g 4.73 g and

Immediately, it turned milky, with a whitish precipitate sticking to the edges of the beaker.

Table 1. The measurements taken for the Lab.

CALCULATIONS BALANCED EQUATION FOR THE DOUBLE REPLACEMENT REACTION

THEORETICAL

Jonathan Sterling

MASS OF REACT COMPLETELY

PRECIPITATE,

WHEN

2.19

G

OF

Jonathan Sterling

EXPERIMENTAL MASS OF

FORMED

EXPERIMENTAL ERROR

Variable

Value

balanced equation for double replacement reaction Theoretical mass of precipitate, when 2.19 g of react completely

1.54 g

Experimental mass of formed Experimental error

4.02 g

Table 2. Contains the calculations for the Lab.

2

161%

Jonathan Sterling

CONCLUSIONS AND QUESTIONS 1.

2.

3.

4.

3

What is another name for a double replacement reaction? Double replacement is now called metathesis; the double replacement and double displacement are deprecated. Give a brief general description of a double replacement reaction. What must one of the products of such a reaction be? Double replacement reactions are generally when two ionic compounds are mixed together, and the cations or anions of each compound switch. One product of a double replacement reaction is always an insoluble solid. Suggest some possible sources of error in this experiment. The percent error in this experiment was massive, and the gap between the experimental and theoretical masses for the zinc phosphate tetrahydrate was extremely large. Because the experiment was done very carefully, I think that the procedure was somehow flawed. Because the experimental mass was much greater than the theoretical, I assume that the procedure filtered something else out along with the expected precipitate, thereby failing to deliver the pure zinc phosphate tetrahydrate precipitate. Define the filtrate and precipitate. A filtrate is the liquid that has been filtered, or remaining after removal of solids via filtration. A precipitate is a solid that separates from a solution.