Fluorine reacts with hydrogen (H) and deuterium (D) to form hydrogen fluoride (HF) and deuterium fluo- ride (DF), where deuterium (21H) is an isotope of hydrogen. Would a given amount of fluorine react with different masses of the two hydrogen isotopes

The question is incomplete, the complete question is;

Fluorine reacts with hydrogen (H) and deuterium (D) to form hydrogen fluoride (HF) and deuterium fluoride (DF), where deuterium (^2_1H) is an isotope of hydrogen. Would a given amount of fluorine react with different masses of the two hydrogen isotopes? Does this violate the law of definite proportion? Explain.

No

Explanation:

The law of Definite proportions as postulated by Proust states that;

"all pure samples of a particular chemical compound contain similar elements combined in the same proportion by mass."

The two isotopes of hydrogen both represent the same element. The only difference between the isotopes is in their atomic mass. However, the both compounds HF and DF contain hydrogen and Florine atoms in exactly the same ratio by mass as postulated by the law of definite proportion.

Hence, the law of definite proportions is not violated.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.