Question

give the chemical formula when potassium reacts with sodium hydroxide solution

Answer 1

when potassium reacts with sodium hydroxide then it forms potassium hydroxide and sodium .
K+NaOH= KOH +Na.
I hope it will help you....

Answer 2

When potassium reacts with sodium hydroxide solution at a temperature 380° C to 450°C , potassium displace sodium and forms potassium hydroxide. 
The reaction is as follows:
K + NaOH → KOH + Na