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.calculate the number of moles of Cl- that are in a 10.00mL sample of the complex.
To find the number of moles of Cl- in the sample, we need to understand the reaction happening in the solution.
The complex [Co(en)2Cl2]Cl contains Co3+ ions and Cl- ions.
According to the given information, when the solution is reduced with Zn through a cation exchange column, the H+ ions are titrated with NaOH solution.
The balanced reaction between H+ ions and NaOH is as follows:
H+ + OH- → H2O
Given that 20.0 mL of 0.10 M NaOH solution is required to titrate the H+ ions, we can find the number of moles of H+ ions in the solution by using the equation:
moles H+ = volume of NaOH solution (L) x concentration of NaOH (mol/L)
= 0.020 L x 0.10 mol/L
= 0.002 mol
Since the ratio of H+ ions to Co3+ ions is 3:1, we can conclude that the number of moles of Co3+ ions in the solution is also 0.002 mol.
The complex [Co(en)2Cl2]Cl contains two chloride ions (Cl-) for every one Co3+ ion.
Therefore, the number of moles of Cl- ions in the 10.0 mL sample can be calculated as follows:
moles Cl- = (moles Co3+ ions x 2) / volume of sample (L)
= (0.002 mol x 2) / 0.010 L
= 0.4 mol/L
Thus, there are 0.4 moles of Cl- ions in a 10.00 mL sample of the complex [Co(en)2Cl2]Cl.
To calculate the number of moles of Cl- in a 10.00 mL sample of the complex, we need to use the information given in the problem and perform a series of calculations.
Step 1: Determine the number of moles of NaOH used in the titration.
Given that 20.0 mL of 0.10 M NaOH solution are required, we can calculate the number of moles of NaOH as follows:
Moles of NaOH = Volume of NaOH (in L) × Concentration of NaOH (in mol/L)
Moles of NaOH = 20.0 mL × (1 L / 1000 mL) × 0.10 mol/L
Step 2: Calculate the number of moles of H+ ions.
As stated in the problem, there are three H+ ions for every Co3+ ion. Since 1 mole of NaOH reacts with 1 mole of H+ ions, the number of moles of H+ ions is the same as the moles of NaOH used in the titration:
Moles of H+ = Moles of NaOH
Step 3: Determine the number of moles of Co3+ ions.
Since there are three H+ ions for every Co3+ ion originally present in the sample, the number of moles of Co3+ ions is equal to one-third of the moles of H+ ions:
Moles of Co3+ = (1/3) × Moles of H+
Step 4: Calculate the number of moles of [Co(en)2Cl2]Cl complex.
Since the initial solution is a 50.0 mL solution of [Co(en)2Cl2]Cl and the sample passed through the cation exchange column is 10.0 mL, the number of moles of [Co(en)2Cl2]Cl in the sample is proportional to the volume ratio:
Moles of [Co(en)2Cl2]Cl = (10.0 mL / 50.0 mL) × Moles of Co3+
Step 5: Calculate the number of moles of Cl- ions.
In the complex [Co(en)2Cl2]Cl, there are two Cl- ions per molecule. Therefore, the number of moles of Cl- ions is double the number of moles of [Co(en)2Cl2]Cl:
Moles of Cl- = 2 × Moles of [Co(en)2Cl2]Cl
Now, you can substitute the calculated values into these equations to find the number of moles of Cl- in the 10.00 mL sample of the complex.