What happens when an excess of sodium hydroxide is added to the cobalt (2) nitrate solution?

What happens when an excess of sodium hydroxide is added to the cobalt (2) nitrate solution? Give the reaction equation and justify the composition of the products.

Explanation of the solution to the problem: first, when sodium hydroxide is added to the solution of cobalt (II) nitrate, a pink precipitate of cobalt (II) hydroxide is formed, with further addition of alkali to the solution, this precipitate will begin to dissolve, due to the formation of sodium hexahydroxocobaltate (II) in the solution, the solution turns light pink. This dissolution is based on the ability of cobalt to form stable complexes. These two reactions are as follows:
Co (NO3) 2 + 2NaOH => Co (OH) 2 + 2NaNO3;
Co (OH) 2 + 4NaOH => Na4 [Co (OH) 6].