Week 06 - Instructor

Week 06 - Instructor - UA GenChem General Chemistry II...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: UA GenChem General Chemistry II General Chemistry II CHEM 152 Unit 2 CHEM 152 Unit 2 Week 6 UA GenChem Week 6 Reading Assignment Chapter 14 Sections 14.6 through 14.9 (calculations - le chtelier) UA GenChem Shifting Equilibrium The equilibrium state for a chemical process can be affected by changes in the concentration of reactants or products, or by varying the temperature and pressure of the system. The direction in which the equilibrium shifts (increasing the concentration of reactants or products) can be many times inferred by analyzing the chemical equation. UA GenChem Butane- Butane- Isobutane Isobutane Equilibrium Equilibrium K = [isobutane] [butane] = 2.5 butane butane isobutane isobutane Let us consider the following equilibrium Shifting Equilibrium UA GenChem Butane Butane Isobutane Isobutane Assume you are at equilibrium with Assume you are at equilibrium with [iso] = 1.25 M and [butane] = 0.50 M. [iso] = 1.25 M and [butane] = 0.50 M. Now add 1.50 M butane. Now add 1.50 M butane. What are the concentrations of [iso] and [butane] What are the concentrations of [iso] and [butane] when the equilibrium is when the equilibrium is re-established? re-established? K = 2.5 K = 2.5 Shifting Equilibrium Q = [isobutane] [butane] = 1.25 0.50 + 1.50 = 0.63 To answer this question we can calculate the reaction To answer this question we can calculate the reaction quotient quotient Q Q and compare it to K: and compare it to K: UA GenChem Butane Butane Isobutane Isobutane Given that Given that Q= 0.63 Q= 0.63 and and K =2.5 K =2.5 . . How can the equilibrium be re-established? How can the equilibrium be re-established? The system must shift to increase Q until Q=K This is done by increasing the concentration of ISOBUTANE and DECREASING that of BUTANE. Adding reactants to an equilibrium shifts the equilibrium toward products Shifting Equilibrium UA GenChem Q = K the reaction is at equilibrium Q < K the reaction will proceed to the right (towards the products) Q > K the reaction will proceed to the left (towards the reactants) Q The Reaction Quotient UA GenChem Le Chateliers Principle Le Chateliers Principle The outcome is governed by the: The outcome is governed by the: LE CHATELIERS PRINCIPLE LE CHATELIERS PRINCIPLE ...if a system at equilibrium is disturbed, the system tends to ...if a system at equilibrium is disturbed, the system tends to shift its equilibrium position to counter the effect of the shift its equilibrium position to counter the effect of the disturbance. disturbance. Changes in concentration, pressure, and temperature affect the position of chemical equilibrium. UA GenChem Le Chateliers Principle Le Chateliers Principle The outcome is governed by the: The outcome is governed by the: LE CHATELIERS PRINCIPLE LE CHATELIERS PRINCIPLE Any stress applied to a system at equilibrium causes the system Any stress applied to a system at equilibrium causes the system...
View Full Document

Page1 / 63

Week 06 - Instructor - UA GenChem General Chemistry II...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online