Final answer:
To determine the mass of zinc in a chemical where the ratio of zinc to copper is 4 to 19, and there are 646 grams of copper, set up a proportion and solve for x. The calculation reveals that there are 136 grams of zinc in the chemical.
Step-by-step explanation:
The ratio of zinc to copper in the chemical is 4 to 19. To find the mass of zinc when there are 646 grams of copper, we can set up a proportion:
4 (zinc) / 19 (copper) = x (zinc) / 646 (copper)
Cross-multiply to solve for x, the mass of zinc:
19x = 4 × 646
19x = 2584
Divide both sides by 19 to solve for x:
x = 2584 / 19
x = 136 grams
The jar of the chemical contains 136 grams of zinc.