Iron metal and oxygen gas combine to form the magnetic oxide of iron, Fe3O4 and 680 kJ of heat. How many kilojoules of heat are generated when 750. grams of iron are reacted with an excess amount of oxygen gas?
3Fe + 2O2 ==> Fe3O4 + 680 kJ
My assumption is 680 kJ for the REACTION as written.
680 kJ x (750 g Fe/3*55.85) = ?
To find the number of kilojoules of heat generated when 750 grams of iron react with an excess amount of oxygen gas, we need to use the given information about the reaction and calculate the heat generated per gram of iron, and then multiply it by the mass of iron.
First, let's find the molar mass of Fe3O4 (iron oxide) by summing up the masses of its constituent elements:
Fe: 55.845 g/mol
O: 15.9994 g/mol
Molar mass of Fe3O4 = (3 * Fe) + (4 * O) = (3 * 55.845 g/mol) + (4 * 15.9994 g/mol) = 231.5356 g/mol
Next, let's calculate the heat generated per mole of Fe3O4.
The reaction stoichiometry tells us that 1 mole of Fe3O4 generates 680 kJ of heat.
Now, let's find the moles of Fe3O4 generated when 750 grams of iron react:
moles of Fe3O4 = mass of iron / molar mass of Fe3O4
moles of Fe3O4 = 750 g / 231.5356 g/mol
Using a calculator, we find:
moles of Fe3O4 ≈ 3.237 mol
Finally, let's calculate the heat generated when 750 grams of iron react:
heat generated = moles of Fe3O4 * heat per mole of Fe3O4
heat generated = 3.237 mol * 680 kJ/mol
Again using a calculator, we find:
heat generated ≈ 2200.76 kJ
Therefore, approximately 2200.76 kilojoules of heat are generated when 750 grams of iron react with an excess amount of oxygen gas.
To determine the amount of heat generated when 750 grams of iron react with an excess amount of oxygen gas, we need to use stoichiometry and the given information about the reaction.
The balanced chemical equation for the reaction of iron and oxygen gas is:
4 Fe + 3 O2 → 2 Fe3O4
From the balanced equation, we can see that 4 moles of iron (Fe) reacts with 3 moles of oxygen gas (O2) to produce 2 moles of Fe3O4 and release 680 kJ of heat.
Now, let's calculate the molar mass of iron (Fe) using the periodic table. The molar mass of iron is 55.845 g/mol.
Next, we'll calculate the number of moles of iron in 750 grams by dividing the mass by the molar mass:
moles of Fe = mass of Fe / molar mass of Fe
moles of Fe = 750 g / 55.845 g/mol
Now, we'll use the stoichiometry of the balanced equation to determine the moles of Fe3O4 produced. From the balanced equation, we know that 4 moles of Fe react to produce 2 moles of Fe3O4.
moles of Fe3O4 = (moles of Fe / 4) * 2
Finally, to find the amount of heat generated, we'll use the ratio between the molar amount of Fe3O4 produced and the heat released (680 kJ):
heat generated = (moles of Fe3O4 / 2) * 680 kJ
By plugging in the values calculated, we can find the answer.