A STUDENT STUDYING THE FE+3- HSCN equilibrium put into a test tube 10.00ml of 2.00 x 10-3 M Fe(NO3)3 with 10.0 mL of 2.00 x 10-3 M HSCN.THE H+ in the resulting solution was manteined at 0.500.By spectrophotometric analysis of the equilibrium solution, the equilibrium concentration of FESCN+2 was found to be 1.00x10-4M.

Question

1.-CALCULATE THE INITIAL MOLARITY OF THE FE+3 AFTER DILUTION BUT BEFORE REACTION OCCURRED.ie, {Fe+}0
2.- CALCULTE THE INITIAL MOLARITY OF HSCN AFTER DILUTION.
3.- CALCULATE THE FE+3 WHICH REMAINED UNREACTED IN SOLUTION.ie, The equillibrium malarity of Fe +3
4.- CALCULATE THE HSCN MOLARITY WHICH REMAINED UNREACTED IN SOLUTION.ie, The equilibrium molarity.
5.- CALCULATE THE VALUE FOR KC FOR THE REACTION

Answer 1

1. Initial (Fe^3) = 2E-3 x (10 mL/20 mL)= ?M

2. Initial HSCN = 2E-3 x (10 mL/20 mL) = ?

3.
...........Fe^3+ + SCN^- ==> FeSCN^2+
initial...1E-3.....1E-3.......0
change.....-x......-x.........x
equil.......................1E-4
So x = 1E-4. Calculate (F3^^3+) and (SCN^-) and from there plug into Kc expresion and solve for Kc.