Answer:
1.6 g
Explanation:
Given a graph of mass of chemical B against mass of chemical A, you want to know how much B is needed for 2.2 g of A.
Graph
When reading a graph of this nature, you must determine the quantity associated with each minor grid line. In each case, there are 5 grid spaces between major grid lines, so the value of each minor grid line is 1/5 of the value of a major grid line.
Horizontally, each minor grid line is (1 gram)/5 = 0.2 grams.
Vertically, each minor grid line is (2 grams)/5 = 0.4 grams.
The value A = 2.2 grams will be found 1 minor grid line to the right of A=2.
The corresponding value of B is 1 minor grid line below B=2, so is ...
2 -0.4 = 1.6 . . . . grams
1.6 grams of chemical B is needed.