Question

Please help me with 3 to 4

Post-Lab Questions 1. Write chemical equations that represent the potential reactions of copper metal with the four metal ion solutions. Based on your observations, which reactions occurred and which did not? Ocde of reactinly smetals MaZn Ni> Pb > Co M 2n Ni, Pb Since reactive than Cu, no and 2.40,), are more Lopper hetol Ma (wo,), N.CNO,), , Po Cao) indi vidally will reaction occur betansn Galvanized steel, used in construction and infrastructure, consists of steel (mostly iron) coated with an outer layer of zinc metal. Based on your observations, how does galvanizing steel protect the steel from corrosion? 2. Why is it not necessary to test the reactivity of the elemental metals with solutions of the same metal ion? To illustrate your explanation, write the equation for the potential chemical reaction using one of the metals studied in this lab 3. 4. Some metals form crusty oxide layers that can flake off to expose dean metal surfaces to moisture and air. Other metals form oxide layers that are durable and relatively impermeable. Use this fact to explain why aluminum, a more active metal than iron, is less susceptible to corrosion. 73 EXPERIMENT 5: REDOX CHEMISTRY-ACTIVITTY OF METALS EXPERIMENT 5

Answer 1

3. Metals are reactive in nature and chemical reactivity depends on each metal and compound with which it is reacting . A metal either loses or gains an electron and becomes ionic and then it reacts with other metal or any solution . So fastly the metal loses electron , it will be more reactive than other .

we can take any common example like Na⁺ and K⁺ , potassium ion is more reactive than sodium ion because it can loose electron faster and reacts .

Now a metal reactivity is tested relatively to other metal like we compare any 2 or more than 2 metals reactivity , so we can do this by doing displacement reaction , IF 2 metals X and Y are there and X replaces Y in a solution , then X will be considered more reactive and will be placed in higher series ( a series which tells about reactivity of metal ions ) .

To test the reactivity of Metal it is not necessary to test in solutions of same metal ions because that would ultimately give same metal ion and same metal ion solution , so we cannot predict exactly that how much reactive is this metal as compared to other . For example if we test reactivity of Cu metal in CuSO₄ solution the reaction will be like Cu + Cu²⁺ -------> Cu²⁺ + Cu

So we cannot say exactly about reactivity of metal Cu .

But if we react Iron Fe with CuSO₄ solution then we can tell about reactivity of Cu and Fe metal , this is most common and basic example that can be illustrated in laboratory also .

If we take a solution of CuSO₄ and put some Fe nails or any iron substance in it and keept it for few hours , we will observe that iron will replace Cu and become Fe²⁺ and Cu²⁺ will become Cu

So we can conclude from this reaction that Fe is more reactive than Cu . This is because of reaction that is occuring :-

Fe + CuSO₄ ------------> FeSO₄ + Cu

4. A metal when reatcs with Oxygen forms an oxide layer on it , now it depends on type of metal that what type will be its oxide layer . Now if oxide form reacts with acids then they will be called as acidic oxides and similarly basic oxides and amphoteric oxides .

usually Metal forms basic oxides , non metals form acidic oxides and amphoteric oxides formed by metalloids .

Aluminium and Iron , both are widely used metal in preparation , construction and industries . Because they react slowly with oxides and corrode very slowly .

Now among aluminium and iron , iron is substance which gets easily corrode in presence of air , moisture and water but aluminium does not corrode easily that means aluminium is less susceptible to corrosion than iron .

This is because aluminium forms an oxide with formula Al₂O₃ which is very impervious to water and oxygen and is highly durable and relatively impermeable . This layer is very tightly bound on the surface of Aluminium and protects it from corrosion .

Reaction occuring is 4 Al + 3O₂ -----------> 2Al₂O₃

where in case of iron is 4Fe + 3O₂ ----------> 2Fe₂O₃ , now this oxide layer of iron is not so much durable and this layer tends to form rust when reacted with water and moisture . So this can be easily corrode as compared to Aluminium