Answer:
C2H4
Explanation:
cause the compound of ethylene is C2H4
The isotopes of an element differ in the number or neutrons whereas the number of protons or electrons of a neutral atom stays the same. The molar mass of the element is based on the percent abundances of different isotopes and the individual molar mass of each isotope.
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.