Thursday, May 10 th : “A” Day Friday, May 11 th : “B” Day Agenda Ch. 15 review – questions/collect Acid Base Webquest review Homework: Ch. 15 vocabulary crossword puzzle Next time: Concept Review Due Crossword Puzzle Due Ch. 15 Test
Acid Base Chemistry Webquest Using technology to enhance learning…plus, it’s really fun! A Webquest is simply a learning tool using the Internet for information. You are about to embark on a quest for knowledge and go where no high school student has gone before…into the world of acid/base chemistry!
I know you’re ready to begin, but first we need to get some stuff out of the way… During this Webquest, you will: 1. Characterize acids and bases based on their definitions and properties. 2. Describe the difference between strong and weak acids and bases. 3. Identify conjugate acid/base pairs. 4. Perform calculations using the self-ionization of water constant, K w. 5. Virtually test the pH of various substances. 6. Order common substances on a pH scale. 7. Calculate pH from [OH - ] and [H 3 O + ] data. 8. Perform a virtual titration and interpret the results. 9. Take a quiz on acids and bases.
OK, now that we’ve got that out of the way, just follow the steps in order and you’ll be on your way… First, go to Wikipedia and do a search on acids. Read about the characteristics and properties of acids and record the following: 1. Definitions (both Arrhenius and Bronsted-Lowry) Did you find any other definitions? If so, include those too. 2. List 3 properties of acids 3. List 3 applications of acids 3. List 2 common mineral acids and 2 common carboxylic acids.Wikipedia
Next, go to Google and search for bases. (This is a little trickier because there are different meanings, but you can do it). Record the following: 1. Definitions of bases (Both Arrhenius and Bronsted-Lowry) 2. List 3 properties of bases 3. List 3 strong bases Now, read the info at Acid Base Info and answer the following questions: 1. Definitions of a strong and weak acid. 2. Definitions of a strong and weak base.GoogleAcid Base Info
OK, you’re pretty good at that, now let’s see if you can match up conjugate acid-base pairs… Go to the following website and read the information about conjugate acids and bases before answering these questions. Conjugate Acid/Base Pairs 1. What is the conjugate base of hydrochloric acid, HCl? 2. The sulfate ion, SO 4 2- is the conjugate base of what acid?Conjugate Acid/Base Pairs
Before you go any farther, show me what you know about the self- ionization constant of water… Read the information in this website Calculation Help to help you figure out these problems and the ones on the next page… 1. Calculate the hydroxide ion concentration [OH - ] in an aqueous solution that has a concentration of hydronium ion [H 3 O + ]equal to 1.55 X 10 -2 M. 2. What is the [H 3 O + ] in a solution of 0.000500 M NaOH? Record your answers in the spaces provided. Calculation Help
You’ve worked pretty hard these last couple of pages, so let’s do something fun next… Open the following link to test the pH of some common substances… pH Test All right, enough fun, let’s get back to business by answering the following questions. 1. Calculate the pH if [H 3 O + ] = 3.5 X 10 -4 M. 2. Calculate pH if [OH - ] is 5.0 X 10 -5 M. pH Test
Now that you know how to measure the pH, let’s see if you can put common substances in order according to their pH. Click on the following to begin pH Scale. Record your answers in the spaces provided. (Hint: Lye is sodium hydroxide, NaOH)pH Scale All right, now you’re ready for the “meat” or “tofu” of this webquest, a Virtual Titration. Remember – if this was a real titration, safety glasses and proper safety equipment would be required! Virtual Titration After going to this website, answer the questions on the next page.
1. What is the initial pH of the solution in the flask? 2. What does the pH tell you about the “type” of solution you are starting with? (Is it an acid or a base?) 3. What ions are present in the flask initially? 4. Begin your virtual titration. 5. Add 5.00 mL of NaOH. 6. What is the new pH? Explain what is happening in the flask. 7. Now add 15.00 mL of NaOH. 8. What is the new pH? Explain what is happening in the flask? 9. Now add 10.00 mL more NaOH to the flask. What happens to the pH? What point has been reached? 10. What is the total volume of solution in the flask now? 11. At pH = 7, what ions and molecules are present in the flask? 12. Is the solution in the flask acidic, basic, or neutral? 13. What is the pH at the equivalence point? 14. Add 5.00 mL more of NaOH. What happens to the pH? 15. Add 5.00 mL of NaOH again. What is the new pH? 16. What is the net ionic equation for this reaction? 17. Given the concentration of the NaOH and the initial volume of the HCl, calculate the concentration of the acid.
All right, you’re almost there. Just take the quiz at the website listed and you’ll be all done! Acid Base Quiz Congratulations acid-base explorers, you’ve completed your task! Make sure your name is on your work and hand it in. If you still have time left, you can go to the following site… Kitchen Chemistry and go into the virtual kitchen.Acid Base Quiz Kitchen Chemistry