How to prove that reaction is possible I have been given task to write possible reaction equations, determine oxidizer, reducer, write corresponding electron-equations and calculate electromotive force (I do not know if that is what you call it in English) of reactions:


Iron reaction with diluted sulfuric acid
Aluminium reaction with solution of sodium hydroxide


Could you be so kind and help me with this task?
The ionic equation for this reaction is:

$\ce{Fe + 2H+ ~(+\;SO4^2- ) -&gt; Fe^2+ + H2 ~(+\;SO4^2- )}$

As two half-reactions, it is seen that the iron is oxidized:

$\ce{Fe -&gt; Fe^2+ + 2e- }$

The reductant (iron) transfers electrons to hydrogen, and is thus itself oxidized.

And the hydrogen is reduced:

$\ce{2H+ + 2e- -&gt; H2}$

The oxidant (hydrogen) removes electrons from iron, and is thus itself reduced.

To calculate the reduction potential you have to solve the following equation:

$\Delta E = E_\text{acceptor} - E_\text{donor} = E_{\ce{2H+/H2}}- E_{\ce{Fe/Fe^2+}}$

$\Delta E = 0\ \mathrm{V} - (-0.41\ \mathrm{V}) = 0.41\ \mathrm{V}$

The reactions runs voluntarily if $\Delta E &gt; 0$.

You can do the same for b).