Question

What happens when sodium or potassium are left outside in the open?

Answer 1

Slow oxidation and hydrolysis of the surface of the metal.

Explanation:

When alkali metal is exposed in the lab, the surface of the metal is oxidized by air or water:

`Na(s) + 1/2O_2(g)rarrNaO(s)`

or

`Na(s)+ H_2O rarr NaOH(aq) + 1/2H_2(g)uarr`

The hydrolysis reaction for both alkali metals is vigorous. The reaction of potassium is especially vigorous. You can destroy relatively large quantities of sodium with ethanol with little trouble; but this procedure would be extremely hazardous with potassium. Gram quantities of potassium (but not sodium) can be destroyed by `25%` `"IPA"` in toluene.

`K(s) + Pr^(i)OH(l) rarr K^+""^(-)OPr^(i) + 1/2H_2(g)uarr`