redox reactivity of metals

[ben4386]

Hi I came across this question

Use the Electrochemical series to predict whether a reaction will occur in each of the following situations. Write an equation for each reaction that you predict will occur

d) An iron nail is placed in 1M HCl solution

e) A plumber uses HCl to clean copper pipes.


for d) the species present would be H+, Cl-, H2O and Oxygen in the air,

why is it that it reacts according to the equation 2H+ + 2e --> H2 g

why not O2 + 4H+ + 4e- since this is a stronger oxidant


for e) apparently a reaction does not take place, perhaps due to Cu being higher in the e series than H+, but again O2 + 4H+ + 4e- is higher and O2 + 2H+ + 2e- for that matter or O2 +H2O + 4e-


methinks it has something to do with rate? i.e. these other reactions occuring to a negligible extent, or the fact that oxygen gas is not available in pure form and not bubbled into the mixture?

An explanation would be handy because atm is seems a bit ambigious.

thanks

[cara.mel]

methinks it has something to do with rate? i.e. these other reactions occuring to a negligible extent, or the fact that oxygen gas is not available in pure form and not bubbled into the mixture?

I am not sure what the RL answer is, but in VCE land your HCl has no oxygen gas in it, so there is no oxygen to react, so those reactions can't happen.

[Pandemonium]

I think O2 has to be dissolved into the water in order to be a participant of the reaction.

[bturville]

yeah, or bubbled into the liquid.