Question

why NaHCO3 & NaOH can't exist together in a solution:

Answer 1

NaHCO₃ and NaOH both undergo chemical reaction and therefore cannot exist together in solution. NaHCO₃ is an acidic salt while NaOH is a base, therefore the two reacts. The reaction is shown below :
NaHCO3  +  NaOH  →Na2CO3  + H2O

Comments

Thanks again, Sir