Question

Fe+3 + SCN- <===> FeSCN+2

You mix the following:

Volume of KSCN solution________ 4.35 mL

Original concentration of KSCN solution_________ 0.00321 M

Volume of ferric ion solution ________4.87 mL

Original concentration of ferric ion solution_________ 0.03753M

Voluume of distilled water _______5.25 mL

You measure the %T of the blank and sample at 447 nm using thesame cuvet. Only FeSCN2+ absorbs

at 446 nm! KSCN and Fe+3 are transparent.

%T of blank _____101.7

%T of sample_____ 49.1

constant [Molarity FeSCN2+ per absorbance]______ 0.001756M/A

********NOTE: This constant is only for this pre-lab*******

Calculate:

a) Millimoles of SCN- originally put in solution _______________mmoles

b) Millimoles of Fe+3 originally put in solution _______________mmoles

c) Total volume of solution _______________ mL

d) Molarity of FeSCN2+ at equilibrium _______________ M

e) Millimoles of FeSCN2+ at equilibrium _______________mmoles

f) Molarity of SCN- at equilibrium _______________ M

g) Molarity of Fe+3 at equilibrium _______________ M

h) Calculated equilibrium constant _______________

so far i found that

a)=0.0140 mmol

b)=0.183 mmol

c)=14.47 mL

i know that i have to use and ICE chart but i am not sure on howto calculate the change in moles from the reactants to theproducts?

if i do (0.014 - x) for the KSCN and (0.183 - x) fot theFe^3+and (0+x) for the FeSCN^+2 i have nothing to set it equal to?that what i dont understand