Question

For this experiment it gives you a slight introduction to the concept of equilibrium using the formation of complex ions which includes FeSCN by determining the most accurate concentration of each of each species in equilibrium. The concentration of equillibrum species will be determine by a spectroctpic method and Beers law.

         2.00 mM KSCN from 20.0 mM KSCN. Use a 50.00 mL volumetric flask.

This solution should be colorless.

         2.00 mM Fe(NO₃)₃ from 20.0 mM Fe(NO₃)₃. Use a 50.00 mL volumetric flask.

This solution should be colorles                       

M1x V1=M2xV2

Solutions	M1	M2	V1	V2	=V2Total stock
KSCN	2.00mM	20.0 mM	50.00ml	?	5.00
FE(NO3)3	2.00mM	20.0 mM	50.00ml	?	5.00

Then you want to get your caliberation so you want to use a 50.00 mL volumetric flask by mixing 3.00 mL of 2.00 mM KSCN (stock) with 5.00 mL of the 200 mM Fe(NO₃)₃. Dilute to the mark with 0.05 M HNO₃.

Solution	2.00 mM Fe3+	2.00 mM SCN-	DI water
1	5.00 mL	1.00 mL	4.00 mL
2	5.00 mL	2.00 mL	3.00 mL
3	5.00 mL	4.00 mL	1.00 mL

Abrobance#	absorbance
1	0.12
2	.019
3	.024
4 Redo	.452

Calculations for the molar absorptivity constant for FeSCN²⁺:

A = ɛlc.

A= 0. 012 L=0.1cm c=5.00 e?

A= 0.019 L= 0.1cm c= 5.00

A= 0.24    L=0.1cm c 5.00

Answer 1