Element Symbol Atomic Mass
Barium Ba 137.327
Hydrogen H 1.00794
Oxygen O 15.9994
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Answer:

Explanation:
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Considering the reaction:

The molar masses of chlorine and chloric acid are:

Now, we develop the stoichiometric relationship to find the mass of chloric acid, considering the molar ratio 3:1 between chlorine and chloric acid, as follows:

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9.96*10⁻²² is the answer, First you find the molar mass of gold, then you turn atoms to moles then moles to grams. There you go you're done!<span />