html5-img
1 / 12

Lab Exam Review

Lab Exam Review. What To Expect. Time Allotted: 75 minutes Stations: 4 (15 min/station) 1 Lab Component for each unit Out of: 40 (10 marks/station) 10% of Final Grade You are allowed to bring your lab book into the exam as a resource.

urbano
Download Presentation

Lab Exam Review

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. Lab Exam Review

  2. What To Expect • Time Allotted: 75 minutes • Stations: 4 (15 min/station) • 1 Lab Component for each unit • Out of: 40 (10 marks/station) • 10% of Final Grade • You are allowed to bring your lab book into the exam as a resource. • You will require a pencil, eraser, ruler, and calculator

  3. What To Expect • Station 1: Determining the Ka of a weak acid • Station 2: Reactions of alcohols • Station 3: Determining molar enthalpy • Station 4: Identifying the type of an unknown solid

  4. Pay Close Attention • As I work through each demo it is your responsibility to note any key procedures or calculations required to complete the lab. You will not be receiving a summary handout.

  5. Station 1 • Purpose: to determine the ionization constant Ka for a weak acid • Materials Provided: • Burette • Retort Stand • Burette clip • 10 mL volumetric pipette • 250 mL Erlenmeyer flask • phenolphthalein indicator • Sodium hydroxide solution (concentration will be given) • Weak Acid (concentration unknown) • The pH of the unknown acid. • You will be required to write a procedure, record observations, and complete the analysis questions required to determine the Ka pH of Acetic Acid used in demo = 2.34

  6. Station 1 • Sample Ka: Acetic Acid • CH3COOH CH3COO- + H3O+ • pH = -log[H3O+] Therefore [H3O+]= 10-pH • This calculation will require an ICF and ICE table!!

  7. Station 2 • Purpose: to identify an alcohol as either a primary, secondary, or tertiary alcohol • Materials Provided: • 2 unknown alcohols (alcohol a and b) • Test tube rack • 5 - 10 mL graduated pipettes • 4 test tubes • 4 rubber stoppers • HCl solution • KMnO 4 solution • You will be required to write a procedure and record observations. Based on your observations you will determine the types of alcohols reacted

  8. Station 2 • Primary alcohols react quickly with KMnO4 • Two step oxidation to carboxylic acids • Secondary alcohols react slowly with KMnO4 • One step oxidation to ketone • Tertiary alcohols do not react with KMnO4 • Cannot undergo oxidation • Primary alcohols do not react with HCl • Separate into two insoluble layers • Secondary alcohols react slowly with HCl • One layer with cloudy precipitate that slowly disappears • Tertiary alcohols react very quickly with HCl • One layer with cloudy precipitate that disappears very quickly

  9. Station 3 • Purpose: To determine the molar enthalpy of solution for a given ionic solid. • Materials Provided: • Coffee cup calorimeter • Thermometer • 100 mL graduated cylinder • Electronic balance • A given ionic solid • Deionized water • You will be required to write a procedure, record observations, and complete the analysis questions required to determine the molar enthalpy of the given ionic solid

  10. Station 3 • Q = mc∆t • m = mass, c = specific heat capacity, ∆t = change in temperature • Specific heat capacity of water = 4.19 J/goC • Density of water = 1.0 g/mL • ∆H = -Q • ∆H = n∆Hsol

  11. Station 4 • Purpose: To classify an unknown substance as a molecular solid, ionic solid, network covalent solid, or metallic solid • Materials Provided: • Unknown Solid • 100 mL beaker • Deionized water • Conductivity meter • Mortar and pestle • Crucible • hotplate • You will be required to write a procedure and record observations. Based on your observations you will determine the type of solid

  12. Station 4

More Related