Unit 3 Chemistry Lab Activity:
Chemical Writing and Chemical Names
The purpose of this activity is to combine different ions and observe whether
they come together to form a precipitate. You can then name the new compound
formed and write the formula for this compound.
Procedure:
1. Take the laminated chart (as shown below) and combine two drops of
cation solution with two drops of anion solution in the appropriate grid
square.
2. Observe the reaction (if any) and record your observation on the data
table below.
3. Repeat the steps until you have combined all twelve possible reactions.
Observations:
a) Use as Y or N to indicate if a precipitate (cloudiness) formed.
b) Fill in your observations of all precipitates formed (color and level of
cloudiness eg. Slightly cloudy, or very cloudy)
Ions
Ag+
Cl1.Y Slightly
cloudy,
CO322.Y very cloudy
OH3.N very cloudy
Co2+
4.N
very cloudy
5.N Slightly
cloudy,
6.N Slightly
cloudy,
7.Y Slightly
cloudy,
8.N very cloudy
Fe3+
9.Y Slightly
cloudy,
10.Y
Slightly cloudy,
11.Y Slightly
cloudy,
12.N very cloudy
Cu2+
Names and formulas of all compounds formed
1. AgCl silver (I) chloride
2. Ag 2(CO3) silver (II) carbonate
3. Ag (OH-) silver (I) hydroxide
4. Co Cl2 cobalt (II) chloride
5. Co (CO3) cobalt (I) carbonate
6. Co (OH-) cobalt (I) hydroxide
7. Fe Cl 3 Iron (I) Chloride
8. Fe2 (CO3)3 Iron (III) Carbonate
9. Fe (OH-)3 Iron (III) Hydroxide
10. Cu Cl2 Copper (I) Chloride
11. Cu (CO3) Copper (I) Carbonate
12. Cu (OH)2 Copper(I) Hydroxide
Photo of spotplate:
Questions:
1. What is happening at the molecular level for a precipitate to form?
(google this)
- the condensation due to cooling of an H20 molecule to form a liquid
2. Suggest a logical reason why the ions in one compound would separate
from each other (eg. Dissolve in water), while they wouldn't be dissolved
in another compound (as they come together in forming a precipitate.)
eg. What forces could be at play here?
-
Because they meet with something different and therefore causing a
chemical reaction that makes them separate from each other.
3. In making formulas of compounds, why would you use parentheses
sometimes?
- Because it includes the whole element/compound and it makes the
reader know that you are making formulas.
4. At what time do you use roman numerals? Is this used in naming, or
making formulas of compounds?
- It is used for naming, for naming you use roman numerals only for
metals and we exclude alkaline metal and earth metals.
5. A) What letters do we use after a formula to indicate the state of the
compound?
- We use the letter (ag) (s) and (L) to indicate the state of the compound.
b) When a compound dissolves in water, how do indicate this with the
formula of the compound?
- you look at the products of the compound after the compound dissolves
in water.
c) At the molecular level, describe the ionic compound when it is
dissolved in water.
- The ionic compound is separated from each other.
Brief reflection statement of what you learned in this activity.
- Something I learned in this activity is being able to observe the
combining of the compounds and also what happens when you combine.