0
Why potassium thiocyanate is added in the titration of sodium thiosulphate with copper?
On addition of the KI to your copper (II) solution, you formed Copper (I) iodine solid and produced the tri-iodide ion. It is the tri-iodide ion that you are titrating with the sodium thiosulfate. The tri-iodine ion is what itercalates into the starch molecules to form the dark blue color you are using as an end point in the titration. Some the the tri-iodide ion formed will adsorb to the surface of the solid copper (I) iodine formed. This must be desorbed for a complete titration. The addition of the potassium thiocyanate, displaces the adsorbed tri-iodine ion, and liberates it for titration.
Still curious? Ask our experts.
Chat with our AI personalities
Rene
Fran
BeauPotassium thiocyanate is added to the titration of sodium thiosulfate with copper to form a yellow complex with Cu2+ ions, which signals the endpoint of the titration. This color change indicates that all the thiosulfate has been reacted with the copper ions, allowing for accurate determination of the thiosulfate concentration.
Add your answer:
Earn +20 pts
Why amnomiun thiocyanate is added in the titration of sodium thiosulphate with copper?
Ammonium thiocyanate is added in the titration of sodium thiosulphate with copper to detect the end point of the reaction. When all the thiosulfate ions react with copper ions, excess copper ions will react with ammonium thiocyanate forming a reddish-brown complex. This color change indicates that all the thiosulfate has reacted and the titration is complete.
Why is ammonium thiocyanate used in iodometry of copper?
Ammonium thiocyanate is used as an indicator in the iodometry of copper because it forms a red complex with copper ions. By adding ammonium thiocyanate to the copper solution, the color change from white to red indicates the end point of the titration, allowing for the determination of copper concentration.
What is the function of NH4CNS in estimation of the amount of copper present in a supplied solution by iodometric method?
NH4CNS (ammonium thiocyanate) is used as an indicator in the estimation of copper by the iodometric method. It forms a red-colored complex with the copper ions, allowing for visual detection of the end-point during the titration process. The indicator changes color when all the copper ions have reacted with the iodine, indicating the endpoint of the titration.
What is the chemical formula for the compound formed by the reaction of copper(II) ions with thiocyanate ions?
The chemical formula for the compound formed by the reaction of copper(II) ions with thiocyanate ions is CuSCN.
Why you use oxalate potassium in formol titration?
Potassium oxalate is used in formol titration as a masking agent to complex with base metals such as iron, copper, and nickel that might interfere with the analysis of formaldehyde. By preventing interference from these base metals, potassium oxalate helps ensure the accuracy and reliability of the formol titration method in determining formaldehyde content.
