## Chemistry 9th Edition

Hydrogen with react with the mass ratio of 1 gram of Hydrogen to 37 grams of Chlorine with $^{37}Cl$ and 1 gram of Hydrogen to 35 grams of Chlorine with $^{35}Cl$. This does not contradict the Law of Definite Proportion as these ratios hold whenever Hydrogen reacts with $^{37}Cl$ and $^{35}Cl$, respectively.