Which law of chemical combination is illustrated by the fact that 168g fe reacts with 72g H2O to from 232g Fe3 O4 and 8gH2?
The law of chemical combination that is illustrated in this question is the Law of Definite Proportions, also known as the Law of Constant Composition. This law states that a given chemical compound will always contain the same elements in the same relative proportions by mass.
To determine which law of chemical combination is illustrated in this question, we need to calculate the mass ratio of iron (Fe) to water (H2O) in the reactants and compare it to the mass ratio of iron(III) oxide (Fe3O4) to hydrogen gas (H2) in the products.
Let's calculate the mass ratio of iron to water in the reactants:
Mass of Fe = 168g
Mass of H2O = 72g
Now, we divide the mass of Fe by the mass of H2O:
Mass ratio = Mass of Fe / Mass of H2O
Mass ratio = 168g Fe / 72g H2O
Mass ratio ≈ 2.33
Now, let's calculate the mass ratio of iron(III) oxide to hydrogen gas in the products:
Mass of Fe3O4 = 232g
Mass of H2 = 8g
Mass ratio = Mass of Fe3O4 / Mass of H2
Mass ratio = 232g Fe3O4 / 8g H2
Mass ratio ≈ 29
Now, we compare the two mass ratios. The mass ratio of iron to water in the reactants is approximately 2.33, while the mass ratio of iron(III) oxide to hydrogen gas in the products is approximately 29. These values are not the same.
According to the Law of Definite Proportions, chemical compounds have fixed, definite compositions. Since the mass ratios in the reactants and products are different, it indicates that the reaction did not go to completion. Some of the reactants are left unreacted or there might be some impurities in the products.
Therefore, the Law of Definite Proportions is not illustrated by the given reaction in the question.