Making Ionic Compouds Lab

NAME: DATE: MAKING IONIC COMPOUNDS LAB

INTRODUCTION

One way that ionic compounds may be formed is through a chemical reaction known as double displacement. In this type of reaction, the cation and anion of one compound switch positions with the cation and anion of another compound to form two new compounds. For example: NaCl (aq) + AgNO3 (aq)  NaNO3 (aq) + AgCl (s) +1 +1 -1 -1 The Na ion takes the place of the Ag ion and the NO3 is replaced by the Cl ions. The mixture creates a precipitate, AgCl, which falls out of solution, while the sodium ions and nitrate ions remain in solution. The overall reaction of interest is known as a net ionic equation and is written as follows: Ag+1 (aq) + Cl-1 (aq)  AgCl (s) The other ions that remain in solution and do not participate are known as spectator +1 -1 ions. These include Na and NO3 in this particular reaction. In this lab, we will combine aqueous solutions of ionic compounds to form new compounds. We will write formulas and name each new compound after making observations of each reaction.

PRELAB 1. See the data table and list all of the cations that will be used in this lab showing their formulas and charges. 2. See the data table and list all of the anions that will be used in this lab showing their formulas and charges. -2 -1 -1 -2 3. In general, what are SO4 , NO3 , OH , and CO3 ? Now name each of the formulas given. 4. Write the double displacement reaction that occurs between NaOH (aq) and FeCl3 (aq) following the sample reaction above. Remember, charges must be balanced in the ionic compounds formed as products.

PROCEDURE

1. Determine the formulas of the ionic compounds made by mixing the following solutions. Combine a cation and anion in each case and write the chemical formula for each ionic compound in the space provided. Remember that the net charge for an ionic compound is zero. 2. Name each compound produced in the lab. 3. Using a 24 well spot plate, combine 3 drops of each compound and mix with a stirring rod or toothpick. Rinse the stirring rod between each combination. 4. Describe your qualitative observations of each new mixture in your data table. Look for colors, precipitates, etc. 5. Show the phase for each compound using (aq) for those that are soluble and (ppt) for those that formed solid precipitates. 6. Wash the spot plate with soap and water when finished. There should not be any trace of left over precipitate in the spot plates. NAME: DATE:

Original AgNO3 MgSO4 (aq) CuSO4 (aq) FeCl3 Compound (aq) (aq) Ions Ag+1 Mg+2 Cu+2 Fe+3

NaCl (aq) Cl-1

-2 Na2CrO4 (aq) CrO4

-2 Na2CO3 CO3 (aq)

NaOH OH-1 (aq)

-3 Na3PO4 PO4 (aq) NAME: DATE:

POST LAB QUESTONS

1. Which of the ionic compounds created were soluble? What do these compounds have in common? Look at their formulas and note any similarities.

2. Which of the ionic compounds were colored? What do these compounds have in common? Look at their formulas and note any similarities.

3. When was it necessary to use Roman numerals in the name of the ionic compounds formed? Why?

4. When and why are parenthesis necessary in a compound’s formula? Give an example.

-1 -1 -2 5. Look at the compounds that were used to create the anions (Cl , CrO4 , CO3 , -1 -3 OH , and PO4 ) in solution. What do they have in common? Why is this significant?

6. Name the 20 compounds that were formed during this experiment. NAME: DATE: