Burgundy Mixture is a formulation used to kill fungi on grapevines. It is made by mixing two compounds, A and B
The ratio by mass of A: B in the mixture is 1:8
(a)
Calculate the mass of A needed in a mixture containing 125 g of B
Mass of A =
g

The mass of A needed for 125 g of B would be 15.64 g

The mass ratio of A to B in the mixture is 1:8

If B is 125 g, then the mass of A would be:

                125 x 1/8

                        = 15.64 g

Thus, the mass of A needed for 125 g of B is 15.64 g.

More on mass ratio can be found here: link

The mass of A needed in a mixture : 15.625 g

Given

A mixture of A and B

Ratio A : B = 1 : 8

mass b = 125 g

Required

The mass of A

Solution

Proust states the Comparative Law that compounds are formed from elements with the same Mass Comparison so that compounds have a constant composition of elements

Mass of A (from the mass of B):

= 1/8 x 125 g

= 15.625 g

the answer is d. 74.02