The reactivity of the group 2 metals

Students will be able to discover that group 1 metals are more reactive than group 2

This experiment should take 30 minutes.

Equipment

Apparatus

• Eye protection
• Test tube rack
• Test tube x 2
• Splint 

Chemicals

• Hydrochloric acid 1 mol dm^–3
• Magnesium
• Fresh calcium

Health, safety and technical notes

• Read our standard health and safety guidance.
• Always wear eye protection.
• Hydrochloric acid is of low hazard, see CLEAPSS Hazcard HC047a.
• Magnesium is pyrophoric and water reactive, see CLEAPSS Hazcard HC059b.
• Calcium is water reactive, see CLEAPSS Hazcard HC019c.

Procedure

1. Fill two test-tubes a quarter with dilute hydrochloric acid.
2. Into one test-tube drop a small piece of magnesium.
3. Into the other, drop a small piece of calcium.
4. Compare the reactivity of the two metals.
5. Drop another bit of magnesium into the first test-tube and put your thumb over the end.
6. When the pressure can be felt, take your thumb off and test the gas with a lighted splint.
7. Record what happens

Notes

Discussion about how to judge the speed of the reaction is advisable.

Remind students about the test for hydrogen.

Calcium can be distributed on pieces of filter paper.

Group 1 is the most reactive group of metals. The Group 1 metals get more reactive the lower they are in the group. Group 2 metals are also reactive.

Questions

1. Which is the more reactive, magnesium or calcium?
2. Write word equations for these reactions.
3. Write formula equations for these reactions

Answers

1. Calcium.
2. Magnesium + hydrochloric acid → magnesium chloride + hydrogen
   1. Calcium + hydrochloric acid → calcium chloride + hydrogen
3. Mg + 2HCl → MgCl₂ + H₂
   1. Ca + 2HCl → CaCl₂ + H₂