How is the reaction of sodium with sodium hydroxide?

There will not be any reaction .Both will remain togather in mixed form i.e.Na+ OH- and HSO3 ions in aquaeous solutionDr. Pradhan

Any reaction between sodium chloride and sodium hydroxide.

the answer is hydrogen

With the presence of an aldehyde and sodium hydroxide, an aldol condensation reaction will occur forming an aldol, and eventually an enal.

It doesn't need balancing - it's already balanced. NaHCO3 + NaOH → Na2CO3 + H2O