The solution of known concentration to use to evaluate Z was prepared as follows:
2.00mL of 0.00201 M KSCN and 18.0 ml 0.200 M Fe (NO3)3. Assume that all of the SCN- has been converted to Fe(SCN)2t in this solution.
Fe3+ SCN- ==== Fe Fe(SCN)2+
I don't really know how to do any of the problem, any ideas?? Thanks!
I don't see a question. Probably it's to evaluate Z but what in the world is Z. By the way, Does your equation have an extra Fe in it?
To solve this problem, you need to use the concept of the equilibrium constant (K). The equation provided represents the formation of a complex ion Fe(SCN)2+. The equilibrium constant for this reaction is defined as:
K = [Fe(SCN)2+] / ([Fe3+][SCN-])
To determine the concentration of Fe(SCN)2+ (denoted as [Fe(SCN)2+]), you first need to determine the initial concentrations of Fe3+ and SCN-.
Given that you have mixed 2.00 mL of 0.00201 M KSCN (potassium thiocyanate) and 18.0 mL of 0.200 M Fe(NO3)3 (iron(III) nitrate), you need to convert the volumes to moles by using the equation:
moles = concentration (M) x volume (L)
1. For KSCN:
moles of KSCN = 0.00201 M x (2.00 mL / 1000 mL/L) = 0.00000402 moles
2. For Fe(NO3)3:
moles of Fe(NO3)3 = 0.200 M x (18.0 mL / 1000 mL/L) = 0.0036 moles
Now that you have the moles of KSCN and Fe(NO3)3, you need to determine the amount of SCN- that reacts with Fe3+ to form Fe(SCN)2+ using a stoichiometric ratio.
From the equation: Fe3+ + SCN- = Fe(SCN)2+
The stoichiometric ratio is 1:1. Therefore, the moles of SCN- that react with Fe3+ are equal to the moles of Fe3+. In this case, it is 0.0036 moles.
Now, you need to determine the concentration of Fe(SCN)2+ at equilibrium ([Fe(SCN)2+]). Since all the SCN- has been converted to Fe(SCN)2+, the moles of Fe(SCN)2+ are also 0.0036 moles.
Next, you need to calculate the volume of the final solution. The volumes added for KSCN and Fe(NO3)3 were 2.00 mL and 18.0 mL, respectively, resulting in a total volume of 20.00 mL.
To convert the moles of Fe(SCN)2+ to concentration, use the equation:
concentration (M) = moles / volume (L)
[Fe(SCN)2+] = 0.0036 moles / (20.00 mL / 1000 mL/L) = 0.18 M
Hence, the concentration of Fe(SCN)2+ in the solution is 0.18 M.