Forming and Naming Ionic Compounds
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. When solutions of some ionic compounds are mixed, the cation
from one and the anion from another form an insoluble compound which appears as cloudy or grainy
solid, called a precipitate. On the other hand, if all cation-anion combinations form soluble pairs, no
precipitate appears. All of the ions remain in solution.
Purpose:
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To mix ions of different kinds and to observe whether they form precipitates
To write the formula for the new compound and to name the product
To observe when ionic substances react to form a product
Reagent solutions
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Sodium phosphate
Potassium hydroxide
Sodium oxalate
Cobalt chloride
Strontium chloride
Potassium ferrocyanide
Sodium carbonate
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Silver nitrate
Copper(II) sulfate
Nickel(II) chloride
Potassium iodide
Lead(II) nitrate
Iron (III) nitrate
Procedure
1. Obtain a paper grid and cover it with a sheet of wax paper.
2. Organize a set of the solutions to be tested according to their positions on the grid.
3. In each grid square place three drops of each solution corresponding to that location.
4. Record any reaction that occurs or cloudiness that develops in Table 1. Note both the color and
texture of the precipitate (use a CLEAN toothpick to help determine texture). If no reaction occurs,
mark NR.
5. Continue mixing and recording until Table 1 is complete.
Cleaning Up
1. Place the wax paper and any used toothpicks in the receptacle located in the front of the room.
2. Wash your hands thoroughly before leaving the laboratory.
Data Presentation
Table 1. Observations of Color and Texture
Na3PO4
PO43−
KOH
OH−
K4Fe(CN)6
Fe(CN)64−
Na2CO3
CO32−
KI
I−
Na2 C2O4
C2O42−
CoCl2
Co2+
Pb(NO3)2
Pb2+
CuSO4
Cu2+
Fe(NO3)3
Fe3+
NiCl2
Ni2+
SrCl2
Sr2+
AgNO3
Ag+
Data Analysis
1. If a reaction occurred, write the correct formula and chemical name for the substance formed.
Na3PO4
PO43−
CoCl2
Co2+
Pb(NO3)2
Pb2+
CuSO4
Cu2+
Fe(NO3)3
Fe3+
NiCl2
Ni2+
SrCl2
Sr2+
AgNO3
Ag+
KOH
OH−
K4Fe(CN)6
Fe(CN)64−
Na2CO3
CO32−
KI
I−
Na2 C2O4
C2O42−