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Catalyst. Draw the coolest picture of equilibrium you possibly can! Show off to your neighbor. What is a conjugate acid/base?. End. Lecture 6.6.5 – Buffers (continued). Today’s Learning Target. 6.8 – I can identify the conjugate acid and base in a chemical reaction.
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Catalyst • Draw the coolest picture of equilibrium you possibly can! Show off to your neighbor. • What is a conjugate acid/base? End
Today’s Learning Target • 6.8 – I can identify the conjugate acid and base in a chemical reaction. • 6.9 – I can explain what a buffer is, draw a titration curve for a buffered solution, and explain why these are essential to maintaining life in humans.
A Problem • Wendy Mata is an 10thgrade student and she is very nervous about her upcoming chemistry exam on acids and bases. • Now Wendy, like many other people, begin to breath rapidly when she gets nervous. • This is known as hyperventilation.
A Problem • Wendy begins to breath very rapidly. • The more she thinks of chemistry, the faster she breaths, which causes her to think even more about chemistry. • The world around Wendy begins to spin. She becomes very dizzy and passes out.
A Problem • An ambulance is quickly called. • When she gets to the hospital, the doctors give her rapid treatment for her condition. • Wendy makes a full recovery and is able to take her chemistry test.
Today’s Focus Question • What caused Wendy to go into shock and how can this be prevented?
I. Buffers • Abufferis a solution that resists a change in pH. • Weak acids have both an acid and a salt (that acts as a base) present at all times. • Same applies for weak bases • Because both acid and base are present, these can react to prevent changes in pH
Example CH3COO- + H2O CH3COOH + OH CH3COO- + H+ CH3COOH CH3COOH + OH- CH3COO- + H2O
Weak Acid and Strong Base Titration Curve Buffering Region
Blood is a Buffer! • Human blood is buffered to have a pH of 7.3 – 7.5. • Carbonicacid in blood and acts as a buffer: CO2 + H2O H2CO3 + HCO3- • Acidosis is when blood becomes to acidic • Alkalosisis when blood becomes to basic
You Are the Doctor! • You have the patient that was discussed on the beginning of class. • With your group (1) Develop a treatment to cure them if is acidosis (2) Develop a treatment to cure them if it is alkalosis
Exit Ticket 1. Label the conjugate acid and base in the following reaction: HCl + NH3 Cl- + NH4+ 2. How do buffers prevent a change in a solutions pH? 3. Draw a titration curve of a weak acid titrated with a strong base. Label the equivalence point and the buffering region.
Learning Log Assessment • Rate yourself 1 – 4 on LTs 6.8 and 6.9
Work Time • You have the remainder of the class period to begin working on your formal lab report • The rough draft for this report will be due Monday-Tuesday February 4th-5th
Closing Time • Test on Friday • Rough Draft of Lab Report due Tuesday