Pereira Posted November 2, 2011 Share Posted November 2, 2011 (edited) Hello, Any help will be appreciated. Q:Determine moles of dichromate ion that reacted with iron(II) in titration (use average volume). My A: 0.0119mol 6 Fe2+ + Cr2O72- + 14 H3O+ 6 Fe3+ + 2 Cr3+ + 21 H2O 4g-Fe2+ 4g*(1mol/558.845g/mol) = 0.0716 moles of Fe (6/0.0716)=1/x x=(0.0716)1/(6) x=0.0119mols of dichromate. My questions are: 1) am I way off in my approach? 2)Why does the question want me to use volume? It seems that it should not be this easy so I assume I am way off. Also the avg volume of Fe solution 6.75mL and the concentration was =0.102mo/L. --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Alright before I submit this thread to publish I tried another approach: molarity(Cr2O7 2-)= (molarity of Fe(II)/6)*(volume of Fe(II)/volume of Cr2O7) =[(0.102mol/L)/6)] * (0.00675L/0.005L) =0.017*1.35 =0.2295 m(Cr2O72-)=215.992 * .1L *0.2295 m=4.95mols *this answer seems like I am more on the right track I think Are either of these very close. Any hints will be greatly appreciated. ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Edited November 2, 2011 by Pereira Link to comment Share on other sites More sharing options...
Pereira Posted November 5, 2011 Author Share Posted November 5, 2011 Recently have gotten a tutor, mods can delete this thread if you want. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now