Acids and Bases

Acids and Bases

ChemistryLowell High School 2006-2007

2/20/07 to …

Agenda

FYI’s Reading Report Acids/Bases Preamble 8

Tuesday, February 20, 2007

FYI RLog 16 TODAY Quiz (chap 15) 2/23 Friday QP 16 (1-49 odd) 3/2 Friday Garden Project 3/5 Monday

(look online) RLog 10/14 3/12 Monday


Reading Log Report On your whiteboard, construct a reading

report for chapter 16 (10 min) Include 3 bullet points and cite section # Interconnected Interesting

Incomprehensible Clarification


Important

Acids/Bases Acid = produces hydrogen (donor) Base = accepts hydrogen (acceptor)

Acidity and Basicity are measured using the pH/pOH scales (range 0-14)

pH = – log [H+] pOH = – log [OH-] pOH + pH = 14 [H+][OH-] = 1 x 10-14


Preamble 8Determine the pH of 100.0 mL of a

1.00 M HCl solution. Suppose you double the volume of the

solution by adding water. What is the new pH? You double the volume once more with water. What is the new pH? If you continue to add more water, what is the maximum pH that can be reached? Explain your answer.


Agenda FYI’s Acid/BasePreamble 8Water’s EquilibriumNeutralization Preamble 9

Wednesday, February 21, 2007

FYI

Quiz (chap 15) 2/23 Friday QP 16 (1-49 odd) 3/2 Friday Garden Project 3/5 Monday



Acids/Bases Acid = produces hydrogen (donor) Base = accepts hydrogen (acceptor)

Acidity and Basicity are measured using the pH/pOH scales (range 0-14)

pH = – log [H+] pOH = – log [OH-] pOH + pH = 14 [H+][OH-] = 1 x 10-14


Preamble 8Determine the pH of 100.0 mL of a

1.00 M HCl solution. Suppose you double the volume of the

solution by adding water. What is the new pH? You double the volume once more with water. What is the new pH? If you continue to add more water, what is the maximum pH that can be reached? Explain your answer.


Water’s Equilibrium Water is ALWAYS in equilibrium

with itself according to the following equation:

2H2O H3O+ + OH-

The equilibrium constant for this reaction is called Kw = 1.0 x 10-14

Kw = ion product constantWednesday, February 21, 2007

Neutralization When an acid and base are put

together, they will neutralize each other.

If the acid and base contain H and OH, the reaction will form water.

H3O+ + OH- 2H2O


Preamble 9 A Lowell student is trying to neutralize 90.0

mL of a 0.400 M solution of the strong base, Sodium hydroxide so he can put it down the drain.

He adds 30.0 mL of a 1.75 M solution of nitric acid. He then adds 240.0 mL of water.

Will the resulting solution be neutral? What will the [H+] and pH be? What is the [OH-] and pOH? Would the solution turn litmus pink?


Agenda FYI’s Conjugate Acid/Base Indicators

Thursday, February 22, 2007

FYI

Quiz (chap 15) 2/23 Friday QP 16 (1-49 odd) 3/2 Friday Garden Project 3/5 Monday



Conjugate Acid/Base Pairs To find the conjugate base of an

acid, remove one H To find the conjugate acid of a

base, add one H Find the conjugate acid/base for

the following: H2SO4, C2H3O2

-, NH3, HBr, NaOH


Indicators Indicators INDICATE pH via color As the pH of the solution changes,

the indicator molecule reacts to the presence of H+ by rearranging itself and forming a different color.

There is no “standard” color for each pH. Red is not always acid, blue is not always base


Agenda FYI’s Quiz Conjugate Acid/Base Indicator Lab

Friday, February 23, 2007

FYI

Quiz (chap 15) TODAY QP 16 (1-49 odd) 3/2

Friday Garden Project 3/5 Monday



Conjugate Acid/Base Pairs To find the conjugate base of an

acid, remove one H To find the conjugate acid of a

base, add one H Find the conjugate acid/base for

the following: H2SO4, C2H3O2

-, NH3, HBr, NaOH


Indicator Lab Questions1. Draw a color line for each of the

indicators in the lab (one end = acidic, other = basic)

2. Compare the color lines to the ones in the book on page 520.

3. Why did the Bromothymol Blue solution turn yellow? What was the reaction?

4. What have you learned about indicators? What were some of the differences between the indicators?


Agenda FYI’s Indicator Lab Finish (10

min) Garden Project Buffers Normality Preamble 10

Monday, February 26, 2007

FYI

QP 16 (1-49 odd) 3/2 Friday

Garden Project 3/5 Monday (look online)

RLog 10/14 3/12 Monday


Acid/Base Lab Questions: (I saw/ I thought)

1. Draw a color line for each of the indicators in the lab (one end = acidic, other = basic)2. Compare the color lines to the ones in the book on page 520. 3. Why did the Bromothymol Blue solution turn yellow? What was the reaction?4. What have you learned about indicators? What were some of the differences between the indicators?


Garden Project Garden center informational brochure Tri-fold, HANDWRITTEN/DRAWN 4 parts that must be included “Documents A-D” are there for your

reference. You may also use web sources if you need more help

Suggestions: Lay out a mock brochure on notebook paper

before making a final version on nice paper Use pens/markers instead of pencil for impact


Buffers A buffer is a mixture of a weak acid

and its conjugate base The conjugate base is typically

balanced with the presence of an alkali or alkaline earth metal (Groups 1/2)

If a base is added, it will react with the weak acid

If an acid is added, it will react with the conjugate base


Strong vs. Weak Acids Weak acids:

HNO2 HF HC2H3O2 HCN

You will need to memorize these lists (suggestion, memorize the strong, all others are weak)


Strong acids:HCl HBr HI HNO3 H2SO4

Normality When an acid or a base is dissolved in

water, it produces a certain amount of H+ or OH-

Normality is the concentration of H+ or OH- in the solution

Often, pH = – log N (instead of –log M)

Equivalent = amount that provides 1 mol of acid or base


Preamble 10 Decide which of the following are strong

vs. weak acids and write out their conjugate bases

Then, if they are weak acids, write out the reaction of a buffered solution with 1) HCl and 2) NaOH

HNO3 HFHClO4 CH3COOHHCl H2S


Agenda FYI’s Titration Titration Lab


FYI

QP 16 (1-49 odd) 3/2 Friday Garden Project 3/5 Monday



Preamble 10 Decide which of the following are strong

vs. weak acids and write out their conjugate bases

Then, if they are weak acids, write out the reaction of a buffered solution with 1) HCl and 2) NaOH

HNO3 HFHClO4 CH3COOHHCl H2S


Titration Titration is a process that determines

the amount/concentration of an unknown substance in a solution

The analyte = the unknown (analyzed) The titrant = substance reacting with

analyte (titrating the analyte) In the Sailin’ the High C’s lab,

Vitamin C = analyte and iodine = titrant


Titration Titration between a strong acid

and a strong base involves neutralization

H+ (from acid) + OH- (from base) H2O

In this reaction, the titration is finished when the pH = 7

The end = the equivalence point


Titration Lab You will be given a sample with an

unknown concentration of sulfuric acid (analyte). Using phenolphthalein as an indicator and sodium hydroxide as your titrant, determine the original concentration of the sulfuric acid solution.

You will be given a buret, distilled water, flasks, and graduated cylinders

Design a procedure for your experiment


Agenda FYI’s Extra Credit Titration Lab Preamble 11

Thursday, March 1, 2007

FYI

QP 16 (1-49 odd) TOMORROW Acid/Base Lab 3/5 Monday Garden Project 3/5 Monday



Extra Credit (bring 1 or 2) Gloves (50) M or L Medicine cups (5) 1 pack Food coloring 1 box baking soda Distilled Water (1 Gallon) 1 25 lb bag of salt (Costco) 1 pack of balloons (12”) (20-25/pack) 1 hour of work after school for Ms. Rotter

Bring these supplies M-F of next week, they will apply to this marking period

1 10lb bag of sugar Straws (100) box of Alka-Seltzer Bottle of Borax 1 large match box Sponges


Acid/Base Titration Writeup You will be doing a formal write-up for

this lab. The sections that should be included are on the website.

In your lab notebook should simply be your data

The write-up (to be peer reviewed) will be due on Monday. Make sure there is a copy for each person in your team.


Acid/Base Titration Determine the concentration of the original

sulfuric acid solution What was the reaction that took place in

your beaker? What are indications that you are

approaching an endpoint? What would be the difference if you had

hydrochloric acid instead of sulfuric acid? What changes would you have seen? Be specific with numbers.

Design an experiment to determine the concentration of hydroxide in an unknown sample.


Preamble 11 What ideas do you have about what

happens when ice is added to water? What happens to both the water and the ice? Use terms such as cooling, heating, melting, freezing, molecular motion/speed and energy.

Draw a series of pictures to represent what happens when ice melts into water. Label as necessary.


Agenda FYI’s Extra Credit QP 16 Review

Friday, March 2, 2007

FYI QP 16 (1-49 odd) TODAY Acid/Base Lab 3/5 Monday Garden Project 3/5 Monday

(look online) RLog 10/14 3/12 Monday QP 10 (1-35 odd) 3/19 Monday QP 14 (1-41 odd) 3/26 Monday RLog 19 3/29 Thursday


Extra Credit (bring 1 or 2) Gloves (50) M or L Distilled Water (1 Gallon) Medicine cups (5) 1 pack Food coloring 1 box baking soda 1 25 lb bag of salt (Costco) Sponges 1 pack of balloons (12”) (20-25/pack) 1 hour of work after school for Ms. Rotter Bring these supplies M-F of next week, they

will apply to this marking period


1 10lb bag of sugar Straws (100) box of Alka-Seltzer Bottle of Borax 1 large match box

QP 16 (8 min) On your whiteboard, put the following

questions from QP 16 Carbon Cavaliers – # 7 + 9 Periodic Pros – # 15 + 17 Avogadro Aces – # 21 + 29 Kinetic Kids – # 23 + 25 Equilibrium Experts – # 33 Reaction Radicals – # 47 + 49 Solubility Stars – # 43 + 45 Valance Veterans – # 39 + 41


Acid/Base Titration Writeup You will be doing a formal write-up for

this lab. The sections that should be included are on the website.

In your lab notebook should simply be your data (PLUS FIRST ANALYSIS QUESTION)

The write-up (to be peer reviewed) will be due on Monday. Make sure there is a copy for each person in your team.


Acids and Bases

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Transcript of Acids and Bases