How would you find the answers to the questions? I appreciate any form of help.

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How would you find the answers to the questions? I appreciate any form of help. Thanks!

(7) Beer's Law plot 4. A student determining the equilibrium constant for the formation of the FeNCs followed the ion procedure in this experiment Part 200 'M Fe' SCN stock were All tri solutions were prepared in 100 ml volumetric flasks. Complete the following calculations and the data in Table 3 on the next page. calculate the initial molar soN ion concentration in standard solutions s3 and s5. Calculate the molar FeNCs ion concentration in standard solutions S3 and S5. (3) Calculate the absorbances for standard solutions S3 and S5. (4) Prepare a Beers Law plot, on the graph paper earlier in this experiment, for the FeNosz ion, using data for standard solutions S1-S6. In Part II, 2.00 x 10-3M Fe3+ on and 2.00 x 10 M SCN ion stock solutions were used to prepare the equilibrium mixtures indicated in Table 4 on the next page. The 5 of the equilibrium solutions (E2-EA) are listed in Table 5 on the next page. Make the following calculations in the spaces provided, and enter the results in Table 5. (5) Calculate the initial Fe t ion concentration in equilibrium mixtures E2-EA. (6) Calculate the initial SCN ion concentration in equilibrium mixtures E2-E4. (7 Express the %T readings for solutions E2-EA as equivalent absorbances. (80 Use your Beer's Law plot to determine the equilibrium FeNCS ion concentration in solutions (g) Determine the equilibrium molar Fest ion concentration in solutions E2-E4. Determine the equilibrium molar SCN ion concent tration in solutions E2-E4. (10) calculate K., for the formation of FeNCs the data ion at the experi mental temperature, using for solutions E2-EA, (12) Use your calculated Kegs from (1) to calculate the mean ke for the formation of FeNOs ion at the experimental temperature. 10

Explanation / Answer

Reaction,

Fe3+(aq) + SCN-(aq) ---> [FeNCS]2+(aq)

steps to follow

1) calculate

initial [Fe3+] = 2 x 10^-1 M x volume of Fe3+ stock solution taken/total volume of solution

initial [SCN-] = 2 x 10^-3 M x volume of SCN- stock solution taken/total volume of solution

Here,

[SCN-] is the limiting reagent, thus,

[SCN-] present = [FeNCS]2+ formed

2) Plot,

absorbance for each standard solution vs [FeNCS]2+ concentration in solution

We get straight line

slope = molar absorptivity

3) Now from reaction solutions (second set)

For each solution, find [FeNCS]2+eq = Absorbance/molar absorptivity found above

4) Find equilibrium concentrations of,

[Fe3+]eq = initial[Fe3+] - [FeNCS]2+eq

[SCN-]eq = initial[SCN-] - [FeNCS]2+eq

5) Find equilibrium constan Kc as,

Kc = [FeNCS]2+eq/[Fe3+]eq.[SCN-]eq

6) average Kc values

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