Which would be the Arrhenius acid and Arrhenius base between HF and KOH

HF is the Arrhenius acid and KOH is the Arrhenius base.

Explanation:

An Arrhenius acid dissociates in water to form H+ ions in solution.

An Arrhenius base dissociates in water to form OH- ions in solution.

Write the equations by breaking the compounds into their elements

HF→ H⁺ + F⁻       HF produces H⁺ when added to water, so it is the acid.

KOH→ K⁺ + OH⁻   KOH produces OH⁻ when added to water, so it is the base.

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.