Chemistry Lab Handout 08 "The Alkaline Earth Group"

Your Name: ___________________________________ Role:______________

Lab Partners: ________________Role:_____ ________________Role:_____

Problem: How can you determine the identity of an unknown Alkaline

Earth group solution?

Hypothesis: _______________________________________________________

_________________________________________________________________

_________________________________________________________________

Materials: spot plates goggles

background paper Potassium Hydroxide unknown sample

Sodium Carbonate Magnesium Nitrate brush

Potassium Sulfate Potassium Dichromate water

Calcium Chloride Strontium Chloride Barium Chloride

Caution:

Procedure:

1. Obtain goggles and wear them for the entire lab!

2. Place the blue spot plate under the Carbonate, Hydroxide, Sulfate,

and Dichromate headings and lined up with the Mg, Ca, Sr symbols.

3. Place the white spot plate below the blue one.

4. Place 3 drops of Sodium Carbonate in each of the five spots under the word Carbonate. Place 3 drops of Potassium Hydroxide in each

of the five spots under the word Hydroxide. Repeat this process

for Potassium Sulfate and Potassium Dichromate.

5. While being very careful not to mix the liquid from one spot to another, place 3 drops of Magnesium Nitrate in each of the four spots across the first row labeled Magnesium. Place 3 drops of Calcium Chloride in each of the four spots across the second row labeled Calcium. Repeat this process for Strontium Chloride in the third row and Barium Chloride in the fourth row.

6. Observe each spot carefully and record in your observations table.

7. Place 3 drops of the unknown in each of the four spots across the

fifth row labeled unknown.

8. Bring the plates to the front lab table for cleaning.

Observations:

Alkaline Earth Metal	Carbonate	Hydroxide	Sulfate	Dichromate
Magnesium
Calcium
Strontium
Barium
unknown

Data: (none)

Diagram:

Conclusion: _______________________________________________________

_________________________________________________________________

_________________________________________________________________

Questions:

1. Was there evidence of a chemical change in any of the spots?

Which of the five indicators of a chemical change?

2. Which Alkaline Earth element is the least active of the four used in this lab? Which is the most active of the four used in this lab?

3. What was the identity of your unknown Alkaline Earth group solution?

4. Which direction on the periodic table does the reactivity of the

Alkaline Earth elements increase?

5. What is the typical charge of the Alkaline Earth metals when they

become ions? Write an ion formation equation for this process.

Answers: