Question

A student has 3.86 g of iron metal. a How many moles of iron does the student have? Show your work. 0.86g Fe 0.0 motfe b Given your answer to (a) and the fact that rust has the formula Fe203, how many moles of oxygen would be required to convert all of the iron to rust? Show your work. c Given your answer to (b), how many grams of oxygen would be required? Show your work. d What would be the mass of rust produced if all of the iron was converted to rust? Show your work.

Answer 1

a. To find the number of moles of iron, divide the mass of iron by its molar mass. The molar mass of iron is 55.845 g/mol.

3.86 g Fe / 55.845 g/mol = 0.069 mol Fe

b. To convert all of the iron to rust, we need enough oxygen to combine with all of the iron to form Fe2O3. The formula for rust is Fe2O3, which means that for every two moles of iron, we need three moles of oxygen. Given the number of moles of iron that we have, we need 3/2 * 0.069 mol = 0.104 mol of oxygen.

c. To find the mass of oxygen required, multiply the number of moles of oxygen by its molar mass. The molar mass of oxygen is 15.999 g/mol.

0.104 mol O2 * 15.999 g/mol = 1.68 g O2

d. To find the mass of rust produced, multiply the number of moles of iron by the molar mass of rust. The molar mass of rust is 159.68 g/mol.

answer: 0.069 mol Fe * 159.68 g/mol = 11.4 g Fe2O3