Fe+3 (aq) + SCN-(aq) ----------> FeSCN+2 (aq)
Total volume,V2 = 5.12 + 4.88 ml = 10 ml
Initial concentration of Fe(NO3)3 = 4.02 x 10-3 M and initial volume = 5.12 ml
Initial concentration of KSCN = 2.01 x 10-3 M and initial volume = 4.88 ml
Initial concentration of ferric ions Fe+3 , M2 = M1V1/V2 = 4.02 x 10-3 x 5.12/10 = 20.58 x 10-4 M
Initial concentration of thiocyanate ion, SCN- , M2 = M1V1/V2 = 2.01 x 10-3 M x 4.88 /10 = 9.81 x 10-4 M
Fe+3 (aq) + SCN-(aq) ----------> FeSCN+2 (aq)
Initial conc. 20.58 x 10-4 M 9.81 x 10-4 M 0
Change in conc -x -x +x
Equilibrium conc 20.58 x 10-4 M -x 9.81 x 10-4 M -x x = 1.40 x 10-4
Equilibrium conc of Fe+3 = 20.58 x 10-4 M - 1.40 x 10-4 = 19.18 x 10-4 M
Equilibrium conc of SCN- = 9.81 x 10-4 - 1.40 x 10-4 = 8.41 X 10-4 M
Equilibrium constant, Kc = [FeSCN+2 ]/[Fe+3 ][SCN-] = 1.40 x 10-4 /(19.18 x 10-4) (8.41 X 10-4) = 1.40/161.3038 = 0.00868
3) The K+ and nitrate ions (NO3-) in the solution do not involve in the reaction. They are known as spectator ions and remain in ionic form. They stay in the solution and do not change.
A student mixes 5.12 mL of 4.02 x 10 M Fe(NO3)3 with 4.88 mL 2.01 x...
A student mixes 5.00 mL 4.00 x 10-3 M Fe(NO3)3 with 5.00 mL 4.00 x 10-3 M KSCN. The student finds that the equilibrium concentration of FeSCN2+ is 5.6 x 10-4M. a. Set up the Kc expression for the following equation. Fe3+ + SCN- ↔ FeSCN2+b. What is the total volume of the solution? _______ mL c. Fill in the following table for the moles of each species.d. Find the concentration for the above ions. e. Calculate Kc for the reaction.
Consider the following: A student mixes 5.00 mL 2.00 × 10−3 M Fe(NO3)3 with 3.00 mL 2.00 × 10−3 M KSCN. She finds that in the equilibrium mixture the concentration of FeSCN2+ is 1.28 × 10−4 M. Find Kc for the reaction Fe3+(aq) + SCN−(aq) ↔ FeSCN2+(aq). a. What is the initial concentration of Fe3+ in the reaction mixture? [Fe3+] = ___ x 10-3 M b. What is the initial concentration of SCN- in the reaction mixture? [SCN-] = ___...
A student mixes 5.00 mL of 2.00 times 10^-3 M Fe(NO_3)_3 with 5.00 mL of 2.00 times 10^-3 M KSCN. She finds that in the equilibrium mixture the concentration of FeSCN2^+ is 1.40 times 10^-4 M. a) What is the initial concentration in solution of the Fe^3+ and SCN^-? b) What is the equilibrium constant for the reaction?
1. A student mixes 5.00 mL of 2.00 x 10 M Fe(NO3)3 with 5.0 mL of 2.00 x 10-3 M KSCN. She finds that in the equilibrium mixture the concentration of FeSCN+2 is 1.2 x 104 M. Find the Kc for the reaction of Fe (aq) + SCN (aq) → FeSCN2(aq) using the following steps. a. Find the initial concentration of Fe and SCN. (Use Equation 4). Record the value in the ICE Chart below. b. What is the equilibrium...
A mixture is prepared by combining 10.20 mL of 1.80 x 10-3 M Fe(NO3)3 with 10.00 mL of 1.68 x 10-3 M KSCN. The solution turns red due to the formation of FeSCN2+. The absorbance is measured and, using a calibration plot, the [FeSCN2+] at equilibrium is found to be 2.20 x 10-4 M. Complete the following ICE table Fe3+ + SCN- ⇌ FeSCN2+ initial (M) (A) (B) (C) change (M) (D) (E) (F) equilibrium (M) (G) (H) (I) What...
4.81 mL of 0.00200 M Fe(NO3)3, 2.85 mL of 0.00200 M KSCN and 2.34 mL of distilled water were mixed. The resulting solution was allowed to attain equilibrium at 24 oC. The absorbance of the equilibrium solution was recorded, and the [FeSCN2+] was determined graphically to be 7.58 x 10-5 M. Part A: Calculate the number of moles of Fe3+ initially added to the solution. Part B: Calculate the number of moles of FeSCN2+ formed in the solution at equilibrium....
Use the following procedure for answering questions given below: 3.00 mL of 2.00 x 10' M solution of Fe(NO3)3 was mixed with 4.00 mL of 2.5 x 10-3 M solution of KSCN and 1.00 mL of 0.5M HNO3. After equilibrium: Fe3+ + SCN FeSCN2+ = was established the equilibrium concentration of FeSCN2+ ions was read from the calibration curve as 5.00 x 10-4 M. 01. The initial concentration of Fe3+ ions (assuming no reaction took place) was: [20] a) 1.00...
A 25.0 mL volume of 0.0200 M Fe(NO3)3 is mixed with 50.0 mL of 0.00200 M NaSCN and 25.0 mL of 0.100 HNO3. The blood-red FeSCN2+ ion forms and the equilibrium is established: Fe3+(aq) + SCN-(aq) <---> FeSCN2+(aq) The equilibrium concentration of FeSCN2+ ([FeSCN2+]) was measured spectrophotometrically and found to be 7.0 x 10-4 mol/L. To calculate the equilibrium constant (Kc) for thr equilibrium system, proceed through the following steps: A. Moles of Fe3+, initial B. Moles of SCN-, initial...
Soln. 2.5x10-3 M Fe(NO3)3 mL 2.5X10-3 M KSCN mL 0.5 M HNO3 mL Absorbance A 5 1 4 0.020 B 5 2 3 0.034 C 5 3 2 0.037 D 5 4 1 0.056 E 5 5 0 0.066 Calibrated at max wavelength of FeSCN2+ = 485.80nm Final concentration of Fe3+ = 5.56*10-5 Using M1V1=M2V2, calculate the initial concentrations of the reactant Fe3+, (m) and SCN- (n) in each solution A-E.
4. When 5.00 mL of 0.500 M Fe (NO3)3 are mixed with 5.00 mL of 0.250 M NaSCN, the following reaction occurs: Fe3+ (aq) + SCN(aq) $ FeSCN2+(aq) At equilibrium the concentration of FeSCN2- is found to be 6.00 x 10-2 M. A. Fill in the table below with the proper numerical values. (Remember to take into account the effects of dilution when calculating the initial molarity of Fe3+ (aq) and SCN'(aq) Fes- (aq) SCN (aq) FeSCN-(aq) Initial Molarity Change...