Chem Questions

asked by @maggieg11 • over 1 year ago • Chemistry • 5 pts

In the colorimetric (color producing) assay for iron used in this lab; potassium thiocyanate, KSCN, is added to produce a deep red colored precipitate. The lab outline suggests that H2O2 may be added to enhance the color. Write a balanced chemical equation showing the function of the peroxide. In your equation identify the oxidizing agent and the reducing agent.

Write a balanced chemical equation that describes the reaction of iron metal with HCl. Identify the oxidizing and reducing agents in your balanced equation.

Add comment
1 answer

Hey Maggieg11! Here is our balanced equation for the first reaction:

Fe+ KSCN+ H2O2----> FeO2 + KSCNH2

Next assign oxidation numbers for each. For the reactants Fe is 0, K is +1, SCN is -1, for the products Fe is +4, O2 is -2, K is +1, SCN is -1, H2 is +1. For rules on assigning oxidation numbers, check out Jule's video!

From these oxidation numbers we can see that Fe was oxidized because it went form having 0 charge to +4 charge, which also means its a reducing agent. And O2 was reduced as it went from having -1 charge to -2, which also means it is an oxidizing agent. For the second reaction of Fe with HCl set up your balanced equation: 2Fe + 6HCl ----> 2FeCl3 +3H2 and do the same thing using oxidation number rules. Hope that helped!

answered by @dashab2 • over 1 year ago