Calculate the equilibrium concentration of [FeSCN2+] in Part Aif 10.0mL of 2.0x10-3M KSCN and 25.00mL of 0.0020M Fe(NO3)3 arediluted to 100.0mL.

Hint: Answer includes 2 significant figures.

Hint: See \"PREPARATION OF STANDARD SOLUTIONS\" on page3-2.

Hint:

PREPARATION OF STANDARD SOLUTIONS

To get solutions with known [FeSCN²⁺], the followingprocess will be used. You will prepare standard solutions by mixingcarefully measured volumes of solutions of Fe³⁺ (usingFe(NO₃)₃ stock solution) and SCN^–(using KSCN stock solution) of known concentrations. These volumesfor standard solutions A–F are listed in the Standard SolutionsTable (Table 3-1) in Part A, step 6. The key to getting aknown concentration of FeSCN²⁺ in each of thesesolutions is that the initial concentration of Fe³⁺ ismuch greater than the initial concentration of SCN^–ion. When the Fe³⁺ concentration is in largeexcess, the equilibrium will shift (according to Le Châtelier’sPrinciple) to the product side until virtually all theSCN^– is converted to FeSCN²⁺. Thusthe equilibrium concentration of FeSCN²⁺ in a standardsolution will be virtually the same as the initial concentration ofSCN^– in the solution. This initial value,[SCN^–]_initial, which equals[FeSCN²⁺] in the mixed standard solution, can becalculated from the volume and molarity of the SCN^–stock solution (mol SCN^– = M × V) andthe final total volume (in L) of the mixed standard solution. Withthese calculated values for [FeSCN²⁺] and the measuredabsorbances of these standard solutions, a Beer’s law plot can beobtained.