For me the answer is E. It is composed of one Ru2+ ion and two F- ions.
Answer:

Explanation:
Hello!
In this case, considering the given chemical reaction:

Thus, by applying the law of rate proportions, we can write:

Whereas the stoichiometric coefficients of reactants are negative due their disappearance and that of the product is positive due to its appearance. In such a way, when we relate the rate of disappearance of hydrogen gas to the rate of formation of hydrogen iodide, we obtain:

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Answer:
it should be 3
Explanation:
because its already above the 4th line so it wouldn't make sense to say 2 4/4