If you pass 10.0mL of a 50.0mL solution of [Co(en)2Cl2]Cl that has been reduced with Zn through a cation exchange column, you will obtain a solution that has three H+ ions for every Co3+ ion that was originally present in the sample. These H+ ions are titrated with 0.10-M NaOH solution. It is found that 20.0mL of NaOH are required.b.) How many moles of Co3+ does this correspond to?

...........Co^3+ ==> Co^?+ + 3H^+

I...........x........0........0
C..........
E...........0.002/3..........0.002
Wouldn't that be 0.002/3 = 0.000667 in the 10.0 mL?

To calculate the number of moles of Co3+ in the solution, we need to determine the number of moles of H+ ions. Then, we can use the stoichiometry of the reaction to find the number of moles of Co3+.

First, let's calculate the number of moles of H+ ions using the volume and concentration of the NaOH solution.

Moles of H+ ions = volume of NaOH solution (L) × concentration of NaOH solution (mol/L)

Given:
Volume of NaOH solution = 20.0 mL = 20.0/1000 L = 0.0200 L
Concentration of NaOH solution = 0.10 M

Moles of H+ ions = 0.0200 L × 0.10 mol/L = 0.00200 mol

Now, since there are three H+ ions for every Co3+ ion, the number of moles of Co3+ can be determined using the stoichiometric ratio.

Moles of Co3+ = (moles of H+ ions) / 3

Moles of Co3+ = 0.00200 mol / 3 = 0.000667 mol

Therefore, passing 10.0 mL of the solution through the cation exchange column resulted in 0.000667 moles of Co3+.