For reaction 3b provide a completely balanced reaction and do it for number 6 also, my response for 3b was:
Cr(s) + 2HCl--> H2(g) + CrCl2+(aq)
My reaction may not be correct but the CrCl2+ is based off my results for the observation I got, which I don't believe are correct... The other two questions are what was the role of H2SO4 in the chromium #11 reaction (I put an acid catalyst because CrO4 to Cr2O7 is not a redox reaction) and the last was what was the role of FeSO4 salt after the addition of H2SO4 to the Cr reagent.
My results for # 3 were no reaction initially, after heating the HCl and Cr(s) , the solution evolved H2 and turned light blue. I have no clue about the product of 6 because I don't believe I had the previous two correct. For reaction 4, the tubes turned dark green after being shaken, and the same happened for reaction 5. Upon adding the zinc powder it precipitated and turned lighter green. Please let me know what you think, I'm attaching the oxidation states sheet with observations. Let me know if you need anything else but I believe I included everything© BrainMass Inc. brainmass.com July 20, 2018, 3:15 am ad1c9bdddf
The details of reactions of Cr and Mn in a lab are discussed.