Question

A 10 gram sample of iron reacts with oxygen to form 18.2 grams of ferric oxide. How many grams of oxygen reacted?

Answer 1

Answer:

$\boxed {\boxed {\sf 8.2 \ grams}}$

Explanation:

According to the Law of Conservation of Mass, the mass of the products must equal the mass of the reactants.

• mass products = mass reactants

In this problem, the reaction is:

$iron + oxygen = ferric \ oxygen$

• The reactants are iron and oxygen. We know the mass of the iron sample is 10 grams.

• The product is ferric oxide. The mass of the ferric oxide sample is 18.2 grams.

$10 \ g + oxygen=18.2 \ g$

We want to find how many grams of oxygen reacted. We have to get the oxygen by itself. 10 is being added to oxygen. The inverse of addition is subtraction. Subtract 10 from both sides of the equation.

$10 \ g - 10 \ g+ oxygen = 18.2 \ g - 10 \ g$

$oxygen= 18.2 \ g - 10 \ g$

$oxygen= 8.2 \ g$

8.2 grams of oxygen reacted with 10 grams of iron to form 18.2 grams of ferric oxide.