Question

why metal k should not taken with HCL acid for reaction

Answer 1

Metal K (pottassium) is basic in nature and HCL( hydrochloric Acid) is acidic in nature.Because acids and bases react very strongly. You can look for reaction of potassium with water - and imagine that hydrochloric acid is much stronger than water.If you check on the reactivity series you would find out that potassuim is one of the most reactive metals. putting it with H+ solutions is very dangerous as it would be very explosive.
KOH ( base ) + HCl ( acid ) --> Salt + Water (Vigorous Reaction)