This has to do with law of conservation of mass I believe but it stumps me. 50g or iron reacts with 21g of oxygen to form how many gram of iron oxide? Is the answer 71g or 29g
To find the answer to this question, you need to apply the law of conservation of mass, which states that matter cannot be created or destroyed during a chemical reaction. In other words, the total mass of the reactants must be equal to the total mass of the products.
To solve this problem, you need to calculate the total mass of the reactants and then compare it to the total mass of the products.
Given:
Mass of iron (Fe) = 50g
Mass of oxygen (O2) = 21g
First, you need to determine the molar mass of each element. The molar mass is the mass of one mole of a substance, expressed in grams. The molar mass of iron (Fe) is approximately 55.845g/mol, and the molar mass of oxygen (O2) is approximately 32.00g/mol.
Next, convert the masses of iron and oxygen into moles by dividing each mass by its molar mass.
Number of moles of iron = Mass of iron / Molar mass of iron
Number of moles of iron = 50g / 55.845g/mol ≈ 0.8948 mol
Number of moles of oxygen = Mass of oxygen / Molar mass of oxygen
Number of moles of oxygen = 21g / 32.00g/mol ≈ 0.6563 mol
Now, using the balanced chemical equation for the reaction between iron and oxygen, determine the stoichiometric ratio between iron and iron oxide. The balanced equation is:
4Fe + 3O2 → 2Fe2O3
According to the balanced equation, for every 4 moles of iron (Fe) reacting, you get 2 moles of iron oxide (Fe2O3) produced.
Using this ratio, you can determine the moles of iron oxide produced.
Number of moles of iron oxide = (Number of moles of iron / 4) × 2
Number of moles of iron oxide = (0.8948 mol / 4) × 2 ≈ 0.4474 mol
Finally, convert the moles of iron oxide into grams by multiplying by the molar mass of iron oxide. The molar mass of iron oxide (Fe2O3) is approximately 159.69g/mol.
Mass of iron oxide = Number of moles of iron oxide × Molar mass of iron oxide
Mass of iron oxide = 0.4474 mol × 159.69g/mol ≈ 71.43g
So, the answer is approximately 71g of iron oxide.
Therefore, the correct answer is 71g, not 29g.