Reactions of Metals and Acids

2P9: Wednesday 10/11/10

Metals + Water: A quick review• Complete the following word equation:

Metal + Water • Are the ‘reactants’ on the left or right of this equation?• Are the ‘products’ on the left or right of this equation?• How do we test for Hydrogen gas?• Complete the following word equation:

______ + Water Magnesium Hydroxide + _____• List the metals in order of decreasing reactivity:–Magnesium, Calcium, Potassium, Sodium–Potassium > Sodium > Calcium > Magnesium

• Why are Potassium and Sodium stored in oil?

Metal Hydroxide + Hydrogen

Reactions of Metals with Acids

• Aim: Observe what happens when metals are added to an acid

• You will need:– Test tube rack– 4 test tubes– Metals: Magnesium, Zinc, Copper– Acids: Hydrochloric acid, Sulphuric acid– Heat proof mat, Bunsen burner, splint– Safety glasses

Experimental Method• Place test tube in rack and add 10cm3 1M Hydrochloric acid• Add a small piece of Magnesium – immediately place clean

test tube (inverted) over the reaction test tube to capture any gas given off

• Once fizzing stops, test gas with a lit splint• Feel the bottom of the reaction test tube to see if the

reaction mixture has become hot• Repeat all of the above steps using Zinc and Copper• Once you have tested all 3 metals with Hydrochloric acid,

repeat all three experiments using Sulphuric acid• Record your observations in a suitable table

• When you have completed your experiment, draw a labelled diagram of your apparatus, detail your method and complete your table of results

Experimental Results: Metals + AcidMetal Acid Observations Gas given off – test

with lit splint

Magnesium Hydrochloric acid Fizzing, test tube heats up

Hydrogen gas

Zinc Hydrochloric acid Few bubbles around surface of metal

Hydrogen gas

Copper Hydrochloric acid No reaction No gas

Magnesium Sulphuric acid Fizzing, test tube heats up

Hydrogen gas

Zinc Sulphuric acid Slightly more bubbles around the surface of metal

Hydrogen gas

Copper Sulphuric acid No reaction No gas

Conclusions

• Metals react with an acid to produce a chemical called a salt. Hydrogen gas is also produced in this reaction.

• General equation for a metal reacting with an acid is:Metal + Acid Salt + Hydrogen

Naming Salts

Salts have a first name and a last name:First Name – comes from the metalLast Name – comes from the acid

Acid name Salt producedHydrochloric acid chlorideSulphuric acid sulphateNitric acid nitrate

Examples of Salts

From our experiments, the reactions which worked were:

•Magnesium + Hydrochloric acid

•Zinc + Hydrochloric acid

•Magnesium + Sulphuric acid

•Zinc + Sulphuric acid

Magnesium Chloride + Hydrogen

Zinc Sulphate + Hydrogen

Magnesium Sulphate + Hydrogen

Zinc Chloride + Hydrogen

Updating our reactivity seriesCopper metal did not react with either Hydrochloric acid or Sulphuric acid. Copper is therefore not as reactive as Magnesium or Zinc.

We can add these metals to our reactivity series:

Potassium Most reactiveSodiumCalciumMagnesiumZincCopper Least reactive