The jar has 200 grams of zinc.
Solution:
Given that , In a certain chemical reaction, the ratio of zinc to copper is 4 to 19.
A jar of the chemical contains 950 grams of copper.
We have to find how many grams of zinc does it contain
Now, we know that,
19 grams of copper ⇒ 4 grams of zinc
Then, 950 grams of copper ⇒ "n" grams of zinc
So, by chris cross method n x 19 = 4 x 950
19n = 4 x 950
19n = 3800
n = 200
Hence, the jar has 200 grams of zinc.