A compound contains 70.18 % oxygen by mass. What mass of this compound would be needed to obtain 48.45 grams of oxygen?

69.036 g of Compound is required to obtain 48.45 g of Oxygen.

Explanation:

Let us assume that the total mass of the compound is 100 g. So it means that this compound weighing 100 is composed 70.18 % of Oxygen or among 100 g of this compound 70.18 g is constituted by oxygen only. Hence, we can make a relation as that,

70.18 g O is present in = 100 g of a Compound

So,

48.45 g of O will be present in = X g of a Compound

Solving for X,

X = 100 g * 48.45 g : 70.18 g

X = 69.036 g of Compound