1 / 5

Percent Reaction and Q

Percent Reaction and Q. Chem 12 Page 509 & 517-520. Percent Reaction. The yield of product measured at equilibrium compared with the maximum possible yield of products. Example: H 2 + I 2 < -- > 2HI [HI] at equilibrium =1.56M [HI] quantitative in forward reaction =2.00M

tegan
Download Presentation

Percent Reaction and Q

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Percent Reaction and Q Chem 12 Page 509 & 517-520

  2. Percent Reaction • The yield of product measured at equilibrium compared with the maximum possible yield of products. Example: H2 + I2 < -- > 2HI [HI] at equilibrium =1.56M [HI] quantitative in forward reaction =2.00M %rxn = [HI]eq/ [HI]frxn x 100% = 1.56M/2.00M x 100% = 78%

  3. Need to Know: • < 50% = reactants favored = small K • > 50% = products favored = large K • > 99% = Quantitative Forward reaction  Totally a forward reaction, no equilibrium

  4. Reaction Quotient, Qc • Identical expression to Kc, but its value is calculated using concentrations that aren’t necessarily found at equilibrium. • If Qc> Kc = shifts to reactants • If Qc< Kc = shifts to products • If Qc = Kc = equilibrium

  5. Practice Problem: Calculate the Q for the following reaction using these equilibrium concentrations: [N2] = 0.10 M; [H2] = 0.30 M; and [NH3] = 0.20 M. Is the system at equilibrium if Kc of the reaction is 0.40? N2 + 3H2 < -- >2NH3 Answer: Not at equilbrium, Q>K, so shift to left (reactants)

More Related