HCl + KOH = KCl + H₂O
KCl - potassium chloride
Wavelength decreases as frequency increases.
Imagine a heart rate graph. As the heart beats faster, frequency increases and the time between heartbeats decreases (wavelength).
Make sense that way?
I think that it will be a colloid. they may appear to be mixture having only one substance but they are not. For example milk and ink.