Note that the emphasis is on the next-to-last syllable (the penultimate syllable), as it true of all words ending with the “furtive patach”. You can find a short teaching on this http://animatedhebrew.com/lectures/index.html under Furtive Patach in chapter 2.
The smichoot form of this noun מזבח, pronounced: meezBACH , could be used in a funny cat picture! Meez Bach haz ben altered! The cat has his paws on the piano keyboard, and glares at the music with a agitated look? If only I could put a top hat on the cat to remember it is spelled with the chet, but I guess the furtive patach rule only goes with chet, not khaf, so that works.
MEEZ BACH HAZ BEN ALTERED!