Suppose a student mixes 5.00 mL of 2.00 x 10 M Fe(NO,), with 4.00 mL of 2.00 x 10- M KSCN and 1.00 ml of water The student then determines the [FENCS] at equilibrium to be 9.25 x 10 M. Find the equilibrium constant for the following reaction. Show all your calcula- tions for each step. Fe + SCN -FENCS Step 1. Calculate the initial number of moles of Fe" and SCN (use Equation 12). moles of Fe* 100105 moles of SCN 80410-6 S00ML o DosooL 2.00101M SCN 400ML . 000400 L 2 00 104u mol Fest •2.0010M D0osooL 1.0e10-5 mel mot sCN 0u D00400L 2.001O 8.0210.6mol

Suppose a student mixes 5.00 mL of 2.00 x 10 M Fe(NO,), with 4.00 mL of 2.00 x 10- M KSCN and 1.00 ml of water The student then determines the [FENCS] at equilibrium to be 9.25 x 10 M. Find the equilibrium constant for the following reaction. Show all your calcula- tions for each step. Fe + SCN -FENCS Step 1. Calculate the initial number of moles of Fe" and SCN (use Equation 12). moles of Fe* 100105 moles of SCN 80410-6 S00ML o DosooL 2.00101M SCN 400ML . 000400 L 2 00 104u mol Fest •2.0010M D0osooL 1.0e10-5 mel mot sCN 0u D00400L 2.001O 8.0210.6mol

Chemistry: The Molecular Science

5th Edition

ISBN:9781285199047

Author:John W. Moore, Conrad L. Stanitski

Publisher:John W. Moore, Conrad L. Stanitski

Chapter12: Chemical Equilibrium

Section12.5: Using Equilibrium Constants

Problem 12.6PSP

See similar textbooks

Similar questions

Nitrogen, hydrogen, and ammonia are in equilibrium in a 1000-L reactor at 550 K. The concentration of N2 is 0.00485 M, H2 is 0.022 M, and NH3 is 0.0016 M. The volume of the container is halved, to 500 L. (a) Calculate the equilibrium constant. (b) Define y as the change in the concentration of nitrogen in the 500-L container. Is y positive or negative? (c) Write the iCe table and express the equilibrium constant in a polynomial in terms of y.
In a particular experiment, the equilibrium constant measured for the reaction, Cl2(g)+NO2(g)Cl2NO2(g), is 2.8. Based on this measurement, calculate AG° for this reaction. Calculate AG° using data from Appendix E at the back of the book and discuss the agreement between your two calculations.
The following question is taken from a Chemistry Advanced Placement Examination and is used with the permission of the Educational Testing Service. Solve the following problem: MgF2(s)Mg2+(aq)+2F(aq) In a saturated solution of MgF2 at 18 C, the concentration of Mg2+ is 1.21103M . The equilibrium is represented by the preceding equation. (a) Write the expression for the solubility-product constant, Ksp, and calculate its value at 18 C. (b) Calculate the equilibrium concentration of Mg2+ in 1.000 L of saturated MgF2 solution at 18 C to which 0.100 mol of solid KF has been added. The KF dissolves completely. Assume the volume change is negligible. (c) Predict whether a precipitate of MgF2 will form when 100.0 mL of a 3.00103 -M solution of Mg(NO3)2 is mixed with 200.0 mL of a .2.00103 -M solution of NaF at 18 C. Show the calculations to support your prediction.. (d) At 27 C the concentration of Mg2+ in a saturated solution of MgF2 is 1.17103M . Is the dissolving of MgF2 in water all endothermic or an exothermic process? Give an explanation to support your conclusion.
Given the following data: PtCl42(aq)+2ePt(s)+4Cl(aq)Ered=0.73VPt2+(aq)+2ePt(s)Ered=1.20V Find Kffor PtCl42- at 25°C.
Use Table 17.1 to find Kffor AuCl4- (aq) at 25°C.
. The solubility product of iron(III) hydroxide is very small: Ksp=41038at 25 °C. A classical method of analysis for unknown samples containing iron is to add NaOH or NH3. This precipitates Fe(OH)3, which can then be filtered and weighed. To demonstrate that the concentration of iron remaining in solution in such a sample is very small, calculate the solubility of Fe(OH)3in moles per liter and in grams per liter.
Given that the Gf for Pb2+(aq) and Cl-(aq) is -24.3 kJ/mole and -131.2 kJ/mole respectively, determine the solubility product, Ksp, for PbCl2(s).
For the reaction 2NO(g)+2H2(g)N2(g)+2H2O(g) it is determined that, at equilibrium at a particular temperature, the concentrations are as follows: [NO(g)] = 8.1 103 M, [H2(g)] = 4.1 105 M, [N2(g)] = 5.3 102 M, and [H2O(g)] = 2.9 103 M. Calculate the value of K for the reaction at this temperature.
Use the solubility product constant from Appendix F to determine whether a precipitate will form if 10.0 mL of 1.0 106 M iron(II) chloride is added to 20.0 mL of 3.0 104 M barium hydroxide.
Write the expression of the reaction quotient for the ionization of HOCN in water.
Because calcium carbonate is a sink for CO32- in a lake, the student in Exercise 12.39 decides to go a step further and examine the equilibrium between carbonate ion and CaCOj. The reaction is Ca2+(aq) + COj2_(aq) ** CaCO,(s) The equilibrium constant for this reaction is 2.1 X 10*. If the initial calcium ion concentration is 0.02 AI and the carbonate concentration is 0.03 AI, what are the equilibrium concentrations of the ions? A student is simulating the carbonic acid—hydrogen carbonate equilibrium in a lake: H2COj(aq) H+(aq) + HCO}‘(aq) K = 4.4 X 10"7 She starts with 0.1000 AI carbonic acid. What are the concentrations of all species at equilibrium?