Question

The titration of 25.0 mL of an iron(II) solution required 18.0 mL of a 0.265 M solution of dichromate to reach the equivalence point. What is the molarity of the iron(II) solution?

Answer 1

6Fe^2+ + Cr2O7^2- ==> 2Cr^3+ + 6Fe^3+

mols Cr2O7^2- = M x L = ?
mols Fe^2+ = 6 x that.
M Fe^2+ = mols Fe^2+/L Fe^2+
(Note: I didn't balanced the equation completely; actually we need only the redox part balanced.

Answer 2

(18ml)(.265M)/1 mole=(25ml)(xM)/6mole

xM=1.14M

Answer 3

[AI-generated answer — Clown Bot]

Well, that's quite the chemical puzzle you've got there. To find the molarity of the iron(II) solution, we can start by setting up the balanced chemical equation:

6Fe^2+(aq) + Cr2O7^-(aq) + 14H+(aq) --> 6Fe^3+(aq) + 2Cr^3+(aq) + 7H2O(l)

From this equation, we can see that it takes 6 moles of Fe^2+ ions reacting with 1 mole of dichromate ions (Cr2O7^-) to reach the equivalence point.

Given that the volume of the dichromate solution used is 18.0 mL and the molarity is 0.265 M, we can calculate the moles of Cr2O7^- used:

moles of Cr2O7^- = volume (L) x molarity
= 0.0180 L x 0.265 mol/L
= 0.00477 mol

Since the stoichiometric ratio of Fe^2+ to Cr2O7^- is 6:1, we can determine the moles of Fe^2+ present in the iron(II) solution:

moles of Fe^2+ = (moles of Cr2O7^-) / 6
= 0.00477 mol / 6
= 0.000795 mol

Now, let's calculate the molarity of the iron(II) solution:

molarity of Fe^2+ solution = moles of Fe^2+ / volume (L)
= 0.000795 mol / 0.0250 L
= 0.0318 M

So, the molarity of the iron(II) solution is approximately 0.0318 M. But enough with the stoichiometry, chemistry can be such a balancing act sometimes!

Answer 4

[AI-generated answer — Explain Bot]

To calculate the molarity of the iron(II) solution, we can use the concept of stoichiometry and the balanced chemical equation for the reaction between iron(II) ions (Fe2+) and dichromate ions (Cr2O7^2-).

The balanced chemical equation for the reaction is:

6 Fe2+ + Cr2O7^2- + 14 H+ -> 6 Fe3+ + 2 Cr3+ + 7 H2O

From the equation, we can see that the ratio of moles of Fe2+ to moles of Cr2O7^2- is 6:1.

Given that 18.0 mL of a 0.265 M solution of dichromate (Cr2O7^2-) was required to reach the equivalence point, we can use this information to calculate the number of moles of Cr2O7^2-:

Moles of Cr2O7^2- = volume (in L) x molarity
= 0.018 L x 0.265 mol/L
= 0.00477 mol

Since the ratio of moles of Fe2+ to moles of Cr2O7^2- is 6:1, the number of moles of Fe2+ can be calculated as:

Moles of Fe2+ = 6 x Moles of Cr2O7^2-
= 6 x 0.00477 mol
= 0.0286 mol

Now, we can calculate the molarity of the iron(II) solution by dividing the number of moles of Fe2+ by the volume of the iron(II) solution in liters:

Molarity of Fe2+ solution = Moles of Fe2+ / Volume of Fe2+ solution (in L)
= 0.0286 mol / 0.0250 L
= 1.14 M

Therefore, the molarity of the iron(II) solution is 1.14 M.