Grade 10 Chemistry Week 5/6 – Metal Reactivity Series Name _______________________
- What is corrosion?
- You are building a house and are considering the following metals as building materials. Comment on how likely each metal is to corrode:
Building metal | Likelihood of corrosion |
Iron
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Aluminium
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Copper
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Tin
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Zinc
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Silver
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Gold
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- Based on what you have learnt about the likelihood of various metals corroding, explain why silver and gold are used in jewellery.
Going further:
- The electrochemical potential measures the reactivity of metals when accepting electrons as compared to hydrogen. Hydrogen has a potential that is defined as 0 Volts.
It is important to realise that a negative potential does not mean that metal cations want to gain electrons. No metal cation ever wants to gain electrons. The negative voltage just means that the metal accepts electrons less eagerly than hydrogen.
Look up the electrochemical potential and complete the table below:
(A good web site to use is: http://www.chemguide.co.uk/physical/redoxeqia/ecs.html)
Electrochemical Potential Equation | Potential (Voltage) |
Li+(aq) + e- -> Li(s) |
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K+(aq) + e- -> K(s) |
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Ca2+(aq) + 2e- -> Ca(s)
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Na+(aq) + e- -> Na(s)
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Mg2+(aq) + 2e- -> Mg(s)
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Al3+(aq) + 3e- -> Al(s)
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Zn2+(aq) + 2e- -> Zn(s)
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Fe2+(aq) + 2e- -> Fe(s)
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Pb2+(aq) + 2e- -> Pb(s)
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2H+(aq) + 2e- -> H2(g)
| 0 volts |
Cu2+(aq) + 2e- -> Cu(s)
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Ag+(aq) + e- -> Ag(s)
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Au3+(aq) + 3e- -> Au(s)
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- A battery is made up of two different metals embedded in an electrolyte which is basically a liquid or solid that contains lots of ions. This allows electricity to move through the electrolyte. For example, you could use sodium chloride (common salt) as an electrolyte. The two metals are called electrodes and the whole arrangement including the electrolyte is referred to as a “cell”.
Predict the voltage obtained from a battery made from a copper and silver electrode:
_________________________________________________________________________
Predict the voltage obtained from a battery made from a copper and zinc electrode:
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What is the maximum possible voltage obtainable from a single cell and what would the electrodes be made out of? __________________________________________________ - We say that the donation/loss of electrons is called oxidation.
We say that the grabbing/gaining of electrons is called reduction.
When magnesium metal reacts with oxygen gas to make magnesium metal, which element is being oxidised and which one is being reduced:
Magnesium is being: oxidised reduced (circle the correct answer)
Oxygen is being: oxidised reduced (circle the correct answer).
- Electrochemical potential is only one measure of reactivity. The vigorousness that a metal reacts with an acid (or even water) is another measure.
Transition metals are hard to predict in terms of acid reactivity and you will not be asked to predict this here.
How does a metal’s acid/water reactivity change as you read down Group 1 of the periodic table (the alkali metals)? Why is there this change?
How does a metal’s acid/water reactivity change as you read down Group 2 of the periodic table (the earth alkali metals)? Why is there this change?
- Metals are structured at the atomic level as crystal structures which makes them strong.
There are three main types of metal crystal structures. Describe each one and list an example of a metal that has this structure.
Body centred cubic:
Face centred cubic:
Hexagonal close packed:
Metal Reactivity Experiment
Aim: To examine whether the electrochemical series can be used to predict the relative reactivity between two different metals.
Hypothesis: The electrochemical series describes the competition between electrons between a metal and a metal ion, with the metal with the lower voltage being in solution as an ion and the metal with the higher voltage being present as a metal or precipitate.
Equipment: metals, metal ion solutions, test tubes, racks, forceps (for aluminium and silver)
Method:
- React a metal with one of five solutions containing metals ions.
- Observe whether the metal in the solution precipitates out or remains in solution. You may need to wait up to 2 minutes to observe a reaction.
- Repeat with a fresh strip of metal and the next solution, making sure your test tube is clean.
- Repeat then with the next metal.
Results:
| Metal ion solutions |
| Mg(NO3)2 | CuSO4 | FeSO4 | Ag(NO3)2 | ZnSO4 |
Mg metal |
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Cu metal |
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Fe metal |
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Zn metal |
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Ag metal |
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Record whether the metal ion solution precipitated its metal or not.
Discussion:
Place the metals in order from least reactive (most eager to precipitate) to most reactive (most eager to remain as an ion in solution and therefore not precipitate out as a metal).
Did this order agree with the electrochemical series? Explain your answer.
Conclusion: The experiment confirmed / did not confirm (circle your answer) the electrochemical series