Question

Hydrogen and chlorine atoms react to form a simple diatomic molecule in a 1:1 ration, that is HCl. The percent isotopic abundances of the chlorine isotopes 35Cl and 37Cl are 75.77% and 24.23%, respectively. The percent isotopic abundances of the hydrogen isotopes are 2H and 3H are 0.015% and 0.001%. (a) How many different HCl molecules are possible, and what are their mass numbers

Answer 1

Answer:

Four different HCl molecules are possible.

1. Mass of $^{2}H^{35}Cl$  = 37 amu
2. Mass of $^{3}H^{35}Cl$ =  38 amu
3. Mass of $^{2}H^{37}Cl$ = 39 amu
4. Mass of $^{3}H^{37}Cl$ = 40 amu

Explanation:

Mass of 2-H isotope = 2 amu

Mass of 3-H isotope = 3 amu

Mass of 35-Cl isotope = 35 amu

Mass of 37-Cl isotope = 37 amu

Different HCl molecules possible are:

1) $^2H+^{35}Cl\rightarrow ^{2}H^{35}Cl$

Mass of $^{2}H^{35}Cl$ = 2 amu + 35 amu = 37 amu

2)  $^3H+^{35}Cl\rightarrow ^{3}H^{35}Cl$

Mass of $^{3}H^{35}Cl$ = 3 amu + 35 amu = 38 amu

3) $^2H+^{37}Cl\rightarrow ^{2}H^{37}Cl$

Mass of $^{2}H^{37}Cl$ = 2 amu + 37 amu = 39 amu

4) $^3H+^{37}Cl\rightarrow ^{3}H^{37}Cl$

Mass of $^{3}H^{37}Cl$ = 3 amu + 37 amu = 40 amu