Catalyst can speed up chemical reaction without being used up or involved in thr reaction..
On the other hand ammonia is a very dangerous chemical which has a pungent smell and effect the eyes of the user. Thus it kept always in the fume exhaust hood for storing and dispensing function.
The pH of ammonia buffer contains ammonium hydroxide (NH₄OH) and a salt of ammonia with a strong acid like (HCl) which produces, ammonium chloride (NH₄Cl) mixture. The evaporation rate of ammonia is so high at room temperature thus on opening of the buffer solution the ammonia get evaporated very fast and the concentration of ammonia decreases which affect the pH of the buffer solution.
Thus the reason to put ammonia buffer in fume hood is explained.
Atoms are the basic units of matter and the defining structure of elements. We count the number of atoms by the total number of elements present in the compound. In this case, we have 1 atom of Si and 2 atoms of oxygen which would have 3 total number of atoms.
