It was the element of aluminium where they predict their properties <span />
The standard Gibbs free energy of formation ΔGf° of Rb(s), H2(g) and Pb(s) are all zero. Similar to enthalpies of formation, the values of the standard Gibbs energies of formation are zero for the elements in their most stable forms at room conditions 298 Kelvin and one atmosphere pressure.
If a metal is less reactive than carbon, it can be extracted from its oxide by heating with carbon. The carbon displaces the metal from the compound, and removes the oxygen from the oxide. This leaves the metal.
I think it's easiest to find the pOH from the given [OH-] first.
-log(1x10^-5)
pOH=5
Then find the pH.
pOH+pH=14
5+pH=14
pH=9
Then find the [H+] using the pH.
antilog(-9) (if you dont have an antilog button use 10^-9)
[H+]=1x10^-9
