CHEMISTRY

Find the equilibrium constant.

1. The equilibrium constant for the reaction,!
Fe3+ + SCN- ⇋ FeSCN2+ (at a specific temperature),
can be determined by first preparing a standard solution of FeSCN2+ and comparing its absorbance of light to an equilibrium system of unknown concentrations.
i.) Standard preparation:
25.0 mL of 0.500 M Fe(NO3)3 + 5.00 mL of 0.00500 M KSCN, Absorbance (A) = 0.700
☝ (excess!)
Calculate the equilibrium concentration of FeSCN2+ for this standard:
ii.) Unknown equilibrium system:
30.0 mL of 0.00400 M Fe(NO3)3 + 20.0 mL of 0.00400 M KSCN, Absorbance (A) = 0.400

******My answer: 221

2.) ! !
!
A student investigated the same equilibrium system as above, but at a new temperature, by first preparing a standard solution:
36.0 mL of 0.300 M Fe(NO3)3 + 4.00 mL of 0.00300 M KSCN, !Astd = 0.525
And then an equilibrium system of unknown concentrations:
25.0 mL of 0.00300 M Fe(NO3)3 + 15.0 mL of 0.00300 M KSCN ; ! A = 0.442
!
!
!
! Calculate the equilibrium constant for this new temperature (to 3 sig figs).

* Ignore the exclamation points.
****My answer: 179

  1. 👍 0
  2. 👎 0
  3. 👁 621

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    FeSCN2+ -> Fe3+ + SCN- Solution is initially dark red. If some Ag+ is added to form AgSCN. what happens to position of equilibrium? what happens ot the color?

  2. Chemistry

    Given the two reactions 1.PbCl2 Pb^2+ + 2 Cl^-, K1= 1.82×10^−10 2. AgCl Ag^+ + Cl^-, K2 = 1.15×10−4 what is the equilibrium constant Kfinal for the following reaction? PbCl2+ 2 Ag^+ 2AgCl+ Pb^2+ This is what i have soo far:

  3. AP Chemistry

    For the system 2SO2(g) + O2(g) 2SO3 (g), change in enthalpy is negative for the production of SO3. At a particular temperature, 8.00 moles of sulfur dioxide and 10.00 moles of sulfur trioxide are introduced into a 2.00 L

  4. chemistry

    What information does an equilibrium constant give about a reaction? A. It tells how long it takes the reaction to reach equilibrium. B. It tells how much energy is required for the reaction to happen. C. It tells what the rate

  1. chemistry

    For the reaction 2A(g) + B(aq) + 3C(l) D(s) + 3E(g), the concentrations at equilibrium are found to be: A: 2.3x10^3 Pa B: 1.8x10^-2 M C: 15.8M D: 12.5M E: 5.6x10^4 Torr Find the numerical value of the equilibrium constant that

  2. chemistry

    For the reaction at equilibrium: 3Fe(s) + 4H2O(g) Fe3O4(s) + 4H2(g), removing some of the product, Fe3O4(s), would: Answer A. Increase the value of the equilibrium constant, K B. No change C. Decrease the value of the equilibrium

  3. Chemistry

    A student mixes 5.0 mL of 0.00200 M Fe(NO3)3 with 5.0 mL 0.00200 KSCN. She finds that the concentration of FeSCN2+ in the equilibrium mixture is 0.000125 M. Follow these steps to determine the corresponding experimental value of

  4. chem

    Given the concentrations, calculate the equilibrium constant for this reaction: I2(g) + Cl2(g)---> 2ICl(g) At equilibrium, the molar concentrations for reactants and products are found to be I2 = 0.50M, Cl2 = 0.60M, and ICl =

  1. chemistry

    Concerning the following reaction at equilibrium: 3Fe(s) + 4H2O(g) Fe3O4(s) + 4H2(g), increasing the concentration of the Fe(s) would: Answer A. Shift the equilibrium to the right B. Shift the equilibrium to the left C. No change

  2. Chemistry

    If the reaction SO2(g) +0.5O2(g) SO3(g) has the equilibrium constant Kc =56, then what is the Kc value for the following reaction? 2SO3 (g) 2SO2 (g) + O2(g) A. -112 B. 3.2 * 10^-4 C. 56 D. 8.9*10^-3 I think the answer would be C

  3. Chemistry

    An aqueous solution of 0.25 M silver nitrate, AgNO3, and 0.25 M iron(II) nitrate, Fe(NO3)2, are allowed to come to equilibrium in the following chemical reaction: Ag+(aq) + Fe2+(aq) Fe3 + (aq) + Ag(s) If the equilibrium constant,

  4. Chem

    There are three questions in particular that I am having problems with. Here they are 1. A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration

You can view more similar questions or ask a new question.