CHEM 1212 1st Edition Lecture 13 Outline of Last Lecture - Practice Problems- Chemical EquilibriumOutline of Current Lecture - Practice Problems- Quadratic Equation- Avoiding the Quadratic EquationCurrent Lecture- H2(g) + I2(g)  2HI(g)The equilibrium constant for the reaction above is 49 at 450 degrees C. 0.22 mole of I2, 0.22 mole of H2, and 0.66 mole of HI were put into an evacuated 1.00 L container:a. The system is at equilibriumb. Reactants needs to be made to get to equilibriumc. Products needs to be made to get to equilibrium- What is the rate expression that corresponds to the reaction mechanism given?o A + B  C fast equilibrium Ratef = kf[A][B] = rater = kr[C] Kf[A][B]=kr[C] [C] = kf/kr([A][B])o C + D  E slow Rate = k’[C][D] Rate = k’(kc)[A][B][D]- A researcher places 1.5 atms of nitrogen dioxide in a flask at 25 degrees C. The researcher then monitors the total pressure of the flask over time as the nitrogen dioxide is allowed to react to produce dinitrogen tetroxide and reach equilibrium. Given the researchers data, what is Kc for this reaction?o 2NO2(g)  N2O4(g)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Time (min) Total P (atm)0 1.5005 1.34910 1.19815 1.04720 .89625 .89630 .896pN2O4 = 0.604pNO2 = 0.292 Answer: Kp = 7.08; Kc = 173- Quadratic Equationo A + B  2Co If one mole of A and 2 moles of B are placed into a 1L flask and allowed to react, what are the concentrations of A,B, and C at equilibrium?o Answer: Kc = (2x)2/(1-x)(2-x), plug into quadratic equation; find x and plug in to find the final concentrations of A, B, and C- Avoiding the Quadratic Equationo Same problem as aboveo Kc = (2x)2/(1-x)(1-x) = (2x)2/(1-x)2o Take square root of both sides; the square root of Kc = 2x/(1-x)- The reaction  N2(g) + O2(g)  2NO(g)o Contributes to air pollution whenever a fuel is burned in air at a high temperature, as in a gasoline engine. At 1500K, K = 1.0x10-5. Suppose a sample ofair has [N2] = 0.80 mol/L and [O2] = 0.20 mol/L before any reaction occurs. Calculate the equilibrium concentrations of reactants and products after the mixture has been heated to 1500K. Write Kc equation Build ICE chart Put expressions in the equilibrium constant equation; Kc = 1.0x10-5 Assume x is much less than .2 which gets rid of the x’s on the bottom of the equation (only make assumptions when x is being subtracted or added) Check to make sure assumption is right X =