lab - 200 M.003#3 Determination of an equilibrium Constant...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
. . 00200 M 002 mL0 05 mL 5M concentrations of FeSCN 2+ are . × - 4 00 10 5M , . × - 8 00 10 5M , and . × - 1 20 10 4M respectively these values can be used to create the cali . . 0200 M 001 mL0 05 mL 5M . . 0200 M 003 mL0 05 mL M ituted into the equation = [ ] A y conc as the y value, in order to find the concentration of FeSCN 2+ . Exp. #3: Determination of an equilibrium Constant November, 15, 2009 Lauren Thomson Lab Partners: Jeffrey Leon & Nicole Thompson CHEM 1A03 Section 23 Pre-lab Questions: 1. Why do you calibrate the spectrophotometer? What will the calibration line be used for? The spectrophotometer must be calibrated as different molecules will absorb different wavelengths of light and the spectrophotometer cannot distinguish which molecule you are working with. The calibration line is obtained by plotting the various absorptions along with their respective concentrations. This line can be used to distinguish an unknown concentration with regards to any absorbency. 2. In an experiment, equal volumes of 0.00200 M FeCl 3 and 0.00300 M NaSCN were mixed together according to the equation: Fe 3+ (aq) + SCN - (aq) FeSCN 2+ (aq) The equilibrium concentration of FeSCN 2+ (aq) was 2.10 x 10 -4 M. Calculate the equilibrium constant for the reaction. Initial Concentrations: C 1 V 1 =C 2 V 2 [Fe 3+ ] = (0.00200M)(1)=C 2 (2) [SCN - ] = (0.00300M)(1)=C 2 (2) C 2 = 1.00 x 10 -3 M C 2 = 1.50 x 10 -3 M Fe 3+ (aq) + SCN - (aq) FeSCN 2+ (aq) I 1.00 x 10 -3 M 1.50 x 10 -3 M 0M C -X -X +X E 1.00 x 10 -3 M – X 1.00 x 10 -3 M – X X kc = ÷ . × - - . × - - x 1 00 10 3 x1 50 10 3 x = . × - x 2 10 10 4 = kc 206 Purpose:
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern