Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Chem 11 - Chemical Reactions Unit
Transcript of Chem 11 - Chemical Reactions Unit
Determining which reagent is limiting
Doing stoich. calculations with LR:
complete reactions amount of XS reagent left
Qualitative vs quantitative
Purpose of titrations mole ratio
stoichiometry calculations with:
reading and solving different kinds of stoich. word problems D5 D5 Avagadro's hypothesis
Convert volume of gas into moles
Perform stoich. calculations with gases Lesson Plan Create a product and determine yield experiment Demo Unit Test Websites Research Project So much content!
The lessons could easily be just lectures and practice problems
Lots of calculations
Can't do experiments at this point Challenges Evaluation Variety Section 3 lessons Introducing stoichiometry Hook (Demo): reaction that gives a precipitate. Is it possible to predict how much we will get? --> Stoichiometry!!! Mini white-board formative assessment Quiz Lectures (that try to involve asking students questions) "Language and Translator" metaphor Working through examples as a class Practice Problems How many moles are in here? competition Logic problem introduction activity Briggs-Rauscher
Reaction 3 6 9 I would extend this demo to be a full class review before the unit test Be careful not to steal this demo from the grade 12 reaction kinetics unit if they are doing it More Fun Things Labs Demos Activities Obvious changing chemical reaction endothermic reaction - barium hydroxide and ammonium chloride Un-demonstrate a dilution of a strong acid Expanding balloon exothermic reaction - decomposition of potassium chlorate Different kinds of chemical reactions experiment/partner quiz Introduction to titration lab Create a product and determine the yield experiment Titration Lab: purity of aspirin students use molecule models to develop their own idea of conservation of mass given a series of chemical equations, students develop their own steps for balancing equations Balancing Equations competition Team teaching research project Magnets for show energy in bond breaking/forming Sandwich Phet simulation http://www.nuffieldfoundation.org/teachers A resource project for teachers. Very user friendly and they have LOTS of demos and experiment ideas in all areas of science. The experiments are also written out nicely with full procedures and discussions. http://chemistry.about.com/od/demonstrationsexperiments/Demonstrations_Experiments.htm A very informal resource with lots of annoying advertisements. Best for demo ideas, experiments that can be done at home and printable resources (periodic tables). http://www.chemtopics.com/index.html A teacher's personal website that has been built up over years of experience. If you are willing to sift through it, there is tons of stuff for experiments, website links, lectures, software, media, handouts. It links you to resources from other websites as well as to things the teacher himself has developed. Heath Lab: The mass of a reaction product - prediction using stoichiometry vs. experimental determination simple materials boring lab change equipment teachers do more than students uses a control to show that a reaction has happened messy hard to weigh final product Produce Barium Sulphate and determine the percent yield Adapted from a slightly more complex experiment found in an old laboratory manual at http://infohouse.p2ric.org/ref/19/18011.pdf Solid Na2SO4
0.5 M BaCl2 solution
Distilled water Hot Plate
Vacuum/gravity filter apparatus
Drying oven Objectives/Important Conclusions Creating a solid product and comparing the experimental mass with the stoichiometrically calculated mass to obtain a percent yield
To know which reactant was limiting
To determine sources of error to explain why the yield is not 100% Barium sulphate is a very fine precipitate. Because of this the experiment may be difficult to obtain accurate results. Modifications/Challenges To learn to do experimental techniques such as:
rinsing a product to remove impurities
heating a mixture to group fine precipitate molecules together
adding strong acid to water slowly The lab says to heat the mixture for an hour before trying to filter it. We would need to do it in less time. The lab calls for vacuum filtration, but if schools don't have the set up for these, gravity filtration would be needed. A different reaction may need to be chosen if any of the above changes/difficult factors don't work. Choose a pharmaceutical company and a drug that they produce:
What is the chemical reaction that they use to produce it?
What quantities of the drug to they make at a time?
What quantities of reagents do they need?
How do they separate the drug from other products?
What is their percent yield?
What equipment/procedures do they use to increase their percent yield?
What purity do they create their medicines at?
How do they test the purity? http://nobel.scas.bcit.ca/chemed2005/tradingPost/TUPM_S2_4_15ChemFunGames.pdf http://www.teachnlearnchem.com/chemistry.htm Various games that have been altered to practice chemistry concepts. You could alter them for any concept that you want the students to have fun practicing. Fun alternatives to jeopardy! Lots of pre-made lesson plans and worksheets. The subject break up into units is different than for the BC curriculum, but they are still helpful. Has a chemical reaction in the diagram below? Explain your answer. PLO: D1
Comprehension What law (discovered by Antoine Lavoisier) has led chemists to the procedure of balancing chemical equations? PLO: D2
Blooms: Knowledge Law of Conservation of Mass No. Bonds have been broken, but no new bonds have been formed. In an acid-base reaction, what are the products?
a) two new ionic compounds
b) a salt
c) a covalent compound
d) water and a salt
e) water PLO: D3
Blooms: Knowledge d) water and a salt You observe that a test tube full of an unknown liquid changes colour when it is placed in sunlight. What kind of reaction is this?
b) double replacement
d) exothermic PLO: D4
Blooms: Application c) endothermic The question will give a chemical reaction where the limiting reagent needs to be found and then stoichiometry calculations need to be performed to calculate the mass of product at the end. PLO: D5
Blooms: Evaluation The question will then explain that a student gave the answer shown below. Where did the student make the mistake and how would you fix it? You are a pyrotechnics professional who specializes in making fireworks. You want a particular kind of firework to be green coloured when it explodes. You know that barium sulphate is a good compound to use for this because it burns a green colour. You want to make 50 grams of barium sulphate. You have an excess amount of sodium sulphate solution, however the required barium chloride solution (2 M) is expensive and you want to use only the amount that you need. What volume of barium chloride do you use? PLO: D5
Blooms: Application Analysis In our experiment we will synthesis Barium sulphate which is also used as a white pigment for paints and is used in whitening paper.
We will use experimental techniques of quantitative transfer, filtration, washing, and heating, and drying to try to get as high of a percent yield as possible.
You'll have to know how to calculate percent yield using stoichiometry and your laboratory data. In our experiment, we produced a relatively small amount of our product. How do you think large industries create millions of kilograms of their products?
They use industrial processes that use very large and complex equipment. Though they are more complicated due to their size, these processes work off of the exact same techniques that we used in the lab today.
The main ingredients in mineral makeups (eye shadows etc) are usually coverage pigments such as zinc oxide (white). Over 900 billion kg of zinc oxide is produced per year.
The industries that make zinc oxide use various processes to synthesis, separate, and ensure purity of their zinc oxide. Through all of these processes, they want to make sure that they are getting as much zinc oxide as possible. They want as close to 100% yield as possible. Introduction Our Experiment Closing