I am really struggling with this equation question...can someone please help me???
Use the following equation to answer the question...
4Fe(s)+3O2(g)---> 2Fe2O3(g)
Heat = -1700kJ
How many grams of rust form when 453kJ of energy is released?
1700 kJ are released when 2 moles Fe2O3 are formed. So 1700/2 = 850 kJ are released for 1 mole Fe2O3 formed. How many moles Fe2O3 do you have from 453 kJ? That will be 453/850 = ??
Convert that to grams. '
Check my thinking.
To answer this question, we need to use the given equation and the provided heat of -1700 kJ. We also need to know the molar mass of rust (Fe2O3) in order to convert the energy in kilojoules to grams.
Here are the steps to solve this problem:
1. Calculate the moles of energy released:
- Divide the given heat (-1700 kJ) by the molar enthalpy (heat) of the reaction. In this case, the molar enthalpy is -1700 kJ since it is given in the equation.
- So, moles of energy released = -1700 kJ / -1700 kJ/mol = 1 mole of energy released.
2. Determine the stoichiometry of the reaction:
- From the balanced equation, we can see that 4 moles of iron (Fe) react with 3 moles of oxygen (O2) to form 2 moles of rust (Fe2O3).
- This means that 2 moles of rust are formed per 4 moles of iron.
- Simplifying, we can say that 1 mole of rust is formed per 2 moles of iron.
3. Calculate the moles of rust formed:
- Since we know that 1 mole of energy released corresponds to the formation of 1 mole of rust, the moles of rust formed is also 1 mole.
4. Determine the molar mass of rust:
- Fe2O3 consists of two iron atoms (2 x atomic mass of iron) and three oxygen atoms (3 x atomic mass of oxygen).
- The atomic mass of iron (Fe) is 55.845 g/mol, and the atomic mass of oxygen (O) is 15.999 g/mol.
- Therefore, the molar mass of Fe2O3 is (2 x 55.845 g/mol) + (3 x 15.999 g/mol) = 159.687 g/mol.
5. Convert moles of rust to grams:
- Multiply the moles of rust formed (1 mole) by the molar mass of Fe2O3 (159.687 g/mol):
- Mass of rust formed = 1 mole x 159.687 g/mol = 159.687 g.
So, when 453 kJ of energy is released, 159.687 grams of rust will form according to the given equation.