Forming and Naming Ionic Compounds

Chemistry Lab Chapter 9

Names ______

______

FORMING AND NAMING IONIC COMPOUNDS

PROBLEM: When do ionic substances react to form a product? What are the names and formulas for these products?

INTRODUCTION: When they dissolve in water, ionic compounds break apart into ions. These ions move about among the water molecules bumping into the other ions and molecules in the solution. When two ionic solutions are mixed several things can happen! In this experiment you will have an opportunity to mix various ionic compounds in solution. Some ions stay dissolved and uncombined in solution even when they are mixed with other ions. We call these ions soluble. When many other ions are mixed, they form compounds which appear as cloudy or grainy precipitates (solids). These substances are insoluble.

In this experiment your task will be to mix ions of different kinds and to observe whether they form precipitates. If a precipitate is formed you will write the formula for the new compound then name the product.

PRELABORATORY ASSIGNMENT:

1.  For the following pairs of ions, write the formula of the compound that you would expect them to form:

a.  barium and hydroxide ______

b.  cobalt (III) and phosphate ______

c.  iron (II) and phosphate ______

d.  silver and the oxalate ion (C2O4)2- ______

2.  Platinum is a transition metal and forms Pt2+ and Pt4+ ions. Write the formulas for the compounds for each of these ions with:

a.  bromide ions ______and______

b.  carbonate ions ______and ______

MATERIALS:

Apparatus Reagents Reagents

Lab apron sodium phosphate potassium hydroxide

Safety goggles sodium sulfide sodium carbonate

Acetate sheet potassium iodide sodium oxalate

Paper grid cobalt chloride lead (II) nitrate

copper (II) sulfate iron (III) nitrate

nickel (II) chloride strontium chloride

silver nitrate

SAFETY: Wear safety goggles and lab aprons at all times in the laboratory.

PROCEDURE:

1.  Obtain laminated paper grid.

2.  Obtain solutions in dropper bottles. You will have to share with others at your lab table.

3.  Hold the dropper vertically one inch above the laminated paper grid and place 1 drop of each solution on the appropriate box. Keep track of those solutions you have used so that you don’t forget any combinations of solutions. BE VERY CAREFUL NOT TO CONTAMINATE THE DROPPERS. DO NOT TOUCH THE DROPPERS TO THE PREVIOUS DROP OR TO THE LAMINATED PAPER GRID.

4.  Examine each mixture carefully from different angles. Record in the appropriate box on your data table the color of any precipitates that form or cloudiness that develops. If no reaction occurs write N.R. (for no reaction) in the appropriate box on your data table.

5.  Continue this process with all the solutions and recording until your entire data table is complete.

6.  You may wash the solutions down the drain. Clean the laminated paper grid, with soap, and dry it for inspection.

DATA TABLE:

Na3PO4
(PO4)3- / KOH
(OH)- / Na2S
S2- / Na2CO3
(CO3)2- / KI
I- / Na2C2O4
(C2O4)2-
CoCl2
Co2+
Pb(NO3)2
Pb2+
CuSO4
Cu2+
Fe(NO3)3
Fe3+
NiCl2
Ni2+
SrCl2
Sr2+
AgNO3
Ag+

ANALYSIS AND CONCLUSIONS:

1. Write the correct formula for each new compound formed in the corresponding box on the grid below: (If no reaction occurred, leave the box blank.)

Na3PO4
(PO4)3- / KOH
(OH)- / Na2S
S2- / Na2CO3
(CO3)2- / KI
I- / Na2C2O4
(C2O4)2-
CoCl2
Co2+
Pb(NO3)2
Pb2+
CuSO4
Cu2+
Fe(NO3)3
Fe3+
NiCl2
Ni2+
SrCl2
Sr2+
AgNO3
Ag+

2. Write the correct chemical name for each new chemical compound formed in the appropriate box.

Na3PO4
(PO4)3- / KOH
(OH)- / Na2S
S2- / Na2CO3
(CO3)2- / KI
I- / Na2C2O4
(C2O4)2-
CoCl2
Co2+
Pb(NO3)2
Pb2+
CuSO4
Cu2+
Fe(NO3)3
Fe3+
NiCl2
Ni2+
SrCl2
Sr2+
AgNO3
Ag+
Na3PO4
(PO4)3- / KOH
(OH)- / Na2S
S2- / Na2CO3
(CO3)2- / KI
I- / Na2C2O4
(C2O4)2-
CoCl2
Co2+
Pb(NO3)2
Pb2+
CuSO4
Cu2+
Fe(NO3)3
Fe3+
NiCl2
Ni2+
SrCl2
Sr2+
AgNO3
Ag+