Gage Bowman 3/5/13
Lab 27
Abstract:
A double replacement reaction is when two different compounds react with each other
and each cation replaces each other (Ax+By>Ay+Bx). The purpose of this experiment is to have
a better understanding of chemical reactions and their equations this is done by observing
different reactions and writing their chemical equations. This was done by observing the
reactions of silver nitrate, Iron(III) nitrate, and Copper(II) nitrate. No sources of error were
noticed, but there were many possible sources an error could have occurred.
Introduction:
A double replacement reaction is when two different compounds react with each other
and each cation replaces each other. Most double replacement reactions occur between two
ionic compounds that are dissolved in water. The equation is Ax+By>Ay+Bx.
A and B are the anions of each compound, and the x and y are the cations. The cations
swap with each anion to form the new compound. Every new compound will produce a
precipitate, gas, or liquid. In this lab the procedure will be to determine the outcome of each
combination. The outcome will be a precipitate, gas, or liquid. Then write a balanced chemical
equation for each combination.
Purpose:
The purpose of this experiment is to have a better understanding of chemical reactions
and their equations, by observing different reactions and writing the chemical equations.
Procedure:
Make sure all pre lab responsibilities are completed. Make a 4 by 3 chart and label 1-4
and A, B, C. Add five drops of silver nitrate in A1-A4. Put five drops of Iron (III) nitrate solution in
B1-B4. Add five drops of copper (II) nitrate solution in C1-C4. Add a different ionic compound
into each solution. Do not let the tip of the micropipet touch each solution the avoid
contamination. Add five drops of sodium phosphate in A1, B1, and C1. Observe if the solutions
precipitate or not. If precipitate record color in not NR. Add five drops of sodium sulfate in A2,
B2, and C2. Observe if the solutions precipitate or not. If precipitate record color in not NR. Add
five drops of sodium hydroxide in A3, B3, and C3. Observe if the solutions precipitate or not. If
precipitate record color in not NR. Add five drops of sodium chloride to A4, B4, and C4. Observe
if the solutions precipitate or not. If precipitate record color in not NR. Use a dropper to pull up
the silver solutions, dispose into container that is provided. Dispose left over solutions down
the sink with water.
A double replacement reaction is when two different compounds react with each other
and each cation replaces each other. The evidence shows that a double replacement reaction
has occurs is if a precipitate occurs. The evidence that will be recorded will be if the solutions
will precipitate and their color. The precautions that should be used when dealing with silver
nitrate is it is poisonous do not let it get on your skin.
Results:
This experiment showed if two compounds that reacted with each other would show a
precipitate that indicated a double replacement reaction. This was shown with the table below
and the chemical equations of each reaction.
A
B
C
1
Precipitate: Yes
Color: Yellow
Precipitate: Yes
Color: White
Precipitate: Yes
Color: Dark Blue
2
Precipitate: No
Color: Clear
Precipitate: No
Color:
Precipitate: No
Color:
3
Precipitate: Yes
Color: Brown
Precipitate: Yes
Color: Bronze
Precipitate: Yes
Color: Blue
Chemical Equations
A)
1. Silver Nitrate + Sodium Phosphate -> Silver Phosphate + Sodium Nitrate
3Ag(NO3)(aq) + Na3PO4 (aq) -> Ag3PO4 (s) + 2NaNO3 (aq)
2. Silver Nitrate + Sodium sulfate-> Silver Sulfate + Sodium Nitrate
2Ag(NO3)(aq) + Na2SO4 (aq)-> Ag2SO(s) + 2NaNO3 (aq)
3. Silver Nitrate + Sodium Hydroxide-> Silver Hydroxide + Sodium Nitrate
Ag(NO3)(aq) + NaOH (aq)-> AgOH(s) +NaNO3 (aq)
4. Silver Nitrate + Sodium Chloride-> Silver Chloride + Sodium Nitrate
Ag(NO3)(aq) + NaCl (aq)-> AgCl(s) +NaNO3 (aq)
4
Precipitate: Yes
Color: White
Precipitate: Yes
Color: Yellow
Precipitate: No
Color:
B)
1. Iron(III) Nitrate + Sodium Phosphate-> Iron Phosphate + Sodium Nitrate
Fe(NO3)3 (aq) + Na3PO4 (aq) -> FePO4 (s) + 3NaNO3 (aq)
2. Iron(III) Nitrate + Sodium sulfate-> Iron Sulfate + Sodium Nitrate
2Fe(NO3)3 (aq) + 3Na2SO4 (aq) -> Fe2(SO4)3 (s) + 6NaNO3 (aq)
3. Iron(III) Nitrate + Sodium Hydroxide-> + Sodium Nitrate
Fe(NO3)3 (aq) + 3NaOH(aq)-> Fe(OH)3 (s) + 3NaNO3 (aq)
4. Iron(III) Nitrate + Sodium Chloride-> + Sodium Nitrate
Fe(NO3)3 (aq) + 3NaCl(aq) -> Fe(Cl)3 (s) + 3NaNO3 (aq)
C)
1. Copper(II) Nitrate + Sodium Phosphate-> Copper Phosphate + Sodium Nitrate
3Cu(NO3)2 (aq) +2 Na3PO4 (aq) -> Cu3(PO4)2(s) + 6NaNO3
2. Copper(II) Nitrate + Sodium sulfate-> Copper Sulfate + Sodium Nitrate
Cu(NO3)2 (aq) + Na2SO4 (aq) -> CuSO4 (s) +2 NaNO3 (aq)
3. Copper(II) Nitrate + Sodium Hydroxide-> Copper Hydroxide + Sodium Nitrate
Cu(NO3)2 (aq) + 2NaOH(aq) -> Cu(OH)2 (s) + 2NaNO3 (aq)
4. Copper(II) Nitrate + Sodium Chloride-> Copper Chloride + Sodium Nitrate
Cu(NO3)2 (aq) + 2NaCl(aq) -> Cu(Cl)2 (s) + 2NaNO3 (aq)
The results show that A1, A3, A4, B1, B3, B4, C1, and C3 all had shown precipitate. A2,
B2, C2, and C4 did not show a precipitate.
Conclusion:
This experiment was performed to better understanding of double replacement
reactions. This was done by observing the reactions of silver nitrate being added to sodium
phosphate, sodium sulfate, sodium hydroxide, and sodium chloride (A1-A4). Also observing
Iron(III) nitrate being added to sodium phosphate, sodium sulfate, sodium hydroxide, and
sodium chloride (B1-B4). Finally Copper(II) nitrate being added to sodium phosphate, sodium
sulfate, sodium hydroxide, and sodium chloride (C1-C4). Almost all of these reactions had
shown a precipitate but some did not. The results show that A1, A3, A4, B1, B3, B4, C1, and C3
all had shown precipitate. A2, B2, C2, and C4 did not show a precipitate.
The purpose of the experiment was accomplished. The purpose was accomplished
because the participants in this experiment all have a greater understanding of double
replacement reactions. The participants have a greater understanding of how to write and
balance these chemical reactions
In this experiment the only thing expected was to see a chemical reaction and use
double replacement reactions. The actual results were not expected. All the results were
correct therefor accurate, valid, and have great precision.
Silver sulfate and sodium nitrate, iron sulfate and sodium nitrate, copper sulfate and
sodium nitrate, and copper chloride and sodium nitrate all did not show a precipitate. B2, B4,
C1 and C4 are all soluble in water. There is a tie between Silver Nitrate and Iron(II) Nitrate for
the most precipitates.
Discussion:
No sources of error were noticed, but there were many possible sources an error could
have occurred. For example the wells could have been contaminated from the previous classes.
The placing of a solution could have been in the wrong well. The equation for silver nitrate
reacting with sodium chloride is Ag(NO3)(aq) + NaCl (aq)-> AgCl(s) +NaNO3 (aq).