1 25 what is p h
TRANSCRIPT
Launch: 1/25 Grab your binder and immediately take a seat!
Place launch paper and Friday’s practice questions on your desk.
Friday’s Quiz Data:
Today’s Objective: I can use the pH scale to characterize acid and base solutions.
94%!
Launch: 1/25 Grab your binder and immediately take a seat!
Place launch paper and Friday’s practice questions on your desk.
Friday’s Quiz Data:
Today’s Objective: I can use the pH scale to characterize acid and base solutions.
89%!
Launch: 1/25 Grab your binder and immediately take a seat!
Place launch paper and Friday’s practice questions on your desk.
Friday’s Quiz Data:
Today’s Objective: I can use the pH scale to characterize acid and base solutions.
95%!
Launch: 1/25 Grab your binder and immediately take a seat!
Place launch paper and Friday’s practice questions on your desk.
Friday’s Quiz Data:
Today’s Objective: I can use the pH scale to characterize acid and base solutions.
94%!
Launch 1/25 1. Draw a picture of
• HCl (a strong acid) dissolved in water
• HF (a weak acid) dissolved in water
Launch 1/25 2. In a complete sentence, describe the difference
between strong and weak acids. (Hint: use the word “dissociation”)
Launch 1/25 3. In the equation, HSO4
- + H2O H2SO4 + OH-, which reactant molecule acts as the base?
a. HSO4-
b. H2O c. H2SO4
d. OH-
Announcements Unit #6 Exam this Thursday!
Ask questions Work with purpose
Class rules I am focusing on this week: interfering with your own or someone else’s learning
leaving seat without permission
January Calendar
Exam
What is pH? Mr. Heffner 1/25/10
Review: What are strong acids/bases?
strong acid + strong base = water + a salt neutralize each other (pH 7)
HI + KOH ?
H+ + l- K+ + OH- + ? H2O + KI
water a salt
an ionic compound
What is pH? pH is…
the concentration of H+ ions in a solution
pH = - log( H+ ) pH = - log( H+ ) pH = - log( H+ )
the molarity of H+ ions
(mol/L) function on a calculator
pH = - log( H+ )
What is pH? The pH scale is not linear
it is logarithmic
Meaning… 1 pH unit = 10 times the acidity
pH = - log( H+ )
stomach acid (pH 1)
is 10X more acidic than
lemon juice (pH 2)
What is pH? For each 1 pH unit difference, add a “0”
This is because the pH scale is logarithmic!
stomach acid (pH 1)
is 10X more acidic than
lemon juice (pH 2) vinegar (pH 3)
is 100X more acidic than
Two “0”s b/c pH difference = 2
soda (pH 4)
is 1000X more acidic than
Three “0”s b/c pH difference = 3
Whiteboards Work in pairs
Trade-off marker every question
Partner without the marker should be checking work at each step!
You have 60 seconds to answer the question Which is more more acidic/basic? How much more acidic/basic?
Lift board only when prompted
Lemon juice (pH 2) Soda (pH 4)
Which is more acidic and by how much?
Ammonia (pH 10) Water (pH 7)
Which is more basic and by how much?
Rainwater (pH 5) 10M HCl (pH 0)
Which is the stronger acid and by how much?
Bleach (pH 12) Baking soda (pH 9)
Which is the stronger base and by how much?
Tomato Lemon
Which is the stronger acid and by how much?
Banana Soap
Which is the stronger base and by how much?
Rainwater Pure water
Which is the stronger acid and by how much?
Drain cleaner Egg whites
Which is the stronger base and by how much?
Practice Questions Practice question worksheet
Binder Re-label your tabs:
1. Launches
2. Notes
3. Practice Questions
4. Handouts/Labs
5. Grades
Exit Slip 1. pH is a measure of
a. the taste of an acid or a base. b. the ability of a solute to dissolve in solution.
c. the concentration of H+ ions in solution. d. the strength of an ion in solution.
Exit Slip 2. The pH scale is
a. logarithmic, meaning that 1 pH unit equals ten times the acidity/basicity
b. logarithmic, meaning that 1 pH unit equals one times the acidity/basicity
c. linear, meaning that 1 pH unit equals ten times the acidity/basicity
d. linear, meaning that 1 pH unit equals one times the acidity/basicity
Exit Slip 3. Of the four different laboratory solutions below,
the solution with the highest acidity has a pH of a. 11. b. 7. c. 5.
d. 3.
Exit Slip 4. How many times more basic is drain cleaner (pH
12) than baking soda (pH 9)? a. 3 b. 30 c. 100
d. 1000
Exit Slip 5. How many times more
acidic is stomach acid than rainwater?
a. 4
b. 10000 c. 40000
d. 100000
Homework Finish practice questions