Question

A 1.0 mL sample of seawater is determined to contain 2.5x10^-14 moles of dissolved gold. What is the relationship (equality) between one mole of gold to grams of gold?

Answer 1

Answer :

According to Avogadro's Hypothesis,

1 mole of substance (Atoms, molecules etc) = Mass of substance equal to its atomic or molar mass.

Hence,

1 mole of Gold Au = Atomic mass of Gold = 196.97 g.

is the required relation.

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Not asked but answering just.

2.5 x 10^-14 mole Au = Molar mass of Au x 2.5 x 10^-14 = 196.97 x 2.5 x 10^-14. = 4.92 x 10^-12.g

2.5 x 10^-14 mole Au = 4.92 x 10^-12.g = 4.92 picogram.

(i picogram = 10^-12 g)

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