Question

In a certain​ chemical, the ratio of zinc to copper is 3 to 19. A jar of the chemical contains 494 grams of copper. How many grams of zinc does it​ contain?

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It contains grams of zinc.

Answer 1

3216 grams of Zn

Explanation:

It is not clear from the question if the ratio is based on the chemical formula, and is thus the ratio of atoms, or if it is based on mass (in g). I'll assume it is based on the numbers of Zn and Cu atoms.

Let's convert the mass of copper, 494 grams, to moles of copper (representative of the number of atoms). The molar mass of copper, Cu, is 63.55 grams/mole.

Moles Cu =(494 grams)/(63.55 grams/mole) = 7.77 moles Cu

If zinc (Zn) is in a ratio of 19/3, we would have:

(19 moles Zn/3 moles Cu)*(7.77 moles Cu) = 49.2 moles of Zn

The molar mass of zinc is 65.38 grams/mole

The mass of 49.2 moles of Zn is:

(49.2 moles Zn)(65.38 grams/mole) = 3216 grams of Zn