I'm doing a lab where I have to identify the oxidization state of Iron. Here's the procedure I had to go through:
Use 0.5 molar concentration of CuSO4, get another beaker and add 0.1 grams of Iron to it. Add the CuSO4 to the beaker with the Iron fillings. Wait for the reaction to occur. Take out the excess water. Use boiling water to remove the unreacted ions. Let the Copper try.
Note that this has all been very generalized but you should get the point.
So the 2 equations I have now are:
Fe + CuSO4 -> FeSO4 + Fe; and
2 Fe + 3 CuSO4 -> Fe2(SO4)3 + 3 Cu
Now I calculate the number of moles of Iron at the beginning of the experiment, let's call it n1.
Now I calculate the mass of the Copper and convert this to moles.
Now I take the moles of Iron and make a ratio with the moles of Copper and divide by lowest value. Here is my confusion, what exactly is the point of doing this?
How would I go about checking whether I have Fe2+ or Fe3+ using everything I have so far?
Looking at the reaction physically, how would I know that CuSO4 is in excess?
I think that the answer to this is that since we can still see the CuSO4 in the beaker, it must be in excess.
Please help me with this assignment, I've struggled for ages in vain. The main part is that I don't get how to check which oxidization state the Iron, or Fe, is in.
:)
It seems to me you should be calculating the moles of Fe to moles of SO4 and dividing by the smaller of the two to get an empirical ratio. If it comes out 1:1 => Fe^+2; if 2-Fe:3-SO4 => Fe^+3. From the experimental data, you should be able to make these calculations.
To determine the oxidation state of iron (Fe) in the reaction, you need to use the concept of redox reactions and stoichiometry. Let's go through the steps:
1. Calculate the number of moles of iron (n1):
- Given the mass of iron added (0.1 grams), convert it to moles using the molar mass of iron (Fe).
- You can find the molar mass of iron by adding up the atomic masses of Fe from the periodic table.
2. Calculate the moles of copper (Cu):
- Since you started with a 0.5 molar concentration of CuSO4, the moles of copper are the same as the moles of CuSO4.
- You can find the moles of copper by multiplying the initial volume of CuSO4 used by the concentration (0.5 M).
3. Determine the ratio of moles of iron to copper:
- Divide the moles of iron (n1) by the moles of copper.
- If the ratio obtained is a simple whole number, it suggests that one mole of iron reacts with that many moles of copper. This ratio can hint at the oxidation state of iron.
4. Identify the oxidation state of iron using the stoichiometry of the reaction:
- In the first reaction, Fe + CuSO4 -> FeSO4 + Cu, the iron is in the +2 oxidation state.
- In the second reaction, 2 Fe + 3 CuSO4 -> Fe2(SO4)3 + 3 Cu, the iron is in the +3 oxidation state.
By comparing the ratios obtained from step 3 with the stoichiometry of the equations, you can determine the oxidation state of iron in your experiment.
Regarding identifying whether CuSO4 is in excess, your initial intuition seems correct. If you can visually observe the presence of CuSO4 after the reaction has occurred, it suggests that it is in excess. Excess copper sulfate would remain unreacted while reacting with the limited amount of iron.
Be sure to follow the procedure accurately, including recording observations and taking into account any molar ratios when analyzing your results. Good luck with your assignment!