The highest mass peaks in the mass spectrum of Br2 occur at m/z 158, 160, and 162. The ratio of intensities of these peaks is approximately 1:2:1. Bromine has two stable isotopes, 79Br (50.7% abundance) and 81Br (49.3% abundance). What molecular species gives rise to each of these peaks? (Include the mass numbers of the isotopes in your answers.)
m/z 158:
m/z 160:
m/z 162:

answer: c

explanation:

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

2b2t

explanation:

2b2t

the ratio of the conjugate base to the acid required to attain the desired ph.