Although the relative molecular mass of bromoethane is 109, there is no peak at m/z=109 in its mass spectrum. Equally sized peaks at m/z=108 and m/z 110 do, however occur. Explain these observations.
2006-09-18 09:06:47 · 3 answers · asked by The d 1 in Science & Mathematics ➔ Chemistry
The mass you would see using mass spec. would be 12 (Carbon) + 12 (Carbon) + 5 (Hydrogens) + 79 (Bromine) = 108. This is for 79 Br the most abundant isotope. However 81 Br also exists. This is a lesser abundant isotope but will still show up on a mass spectrum. With the 81 Br isotope used there will be a peak at 110. Both isotopes were present in the sample that was analyzed.
2006-09-18 17:08:29 · answer #1 · answered by joshoz01 2 · 1⤊ 0⤋
I'm thinking those would be due to the natural occurrence of isotopes of carbon or bromine with differing weights in your bromoethane.
2006-09-18 16:11:06 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Two isotopes of bromine!
Bromine 79 has a relative abundance of 50.69%
Bromine 81 has a relative abundance of 49.31%
2006-09-18 16:12:01 · answer #3 · answered by Dave_Stark 7 · 0⤊ 0⤋