PH lab Honors p 6.notebook
September 23, 2014
Do Now
1. What foods are acidic?
2. What foods are basic?
3. Do you know any substances that are considered an acid or base?
Objectives
1. SWBAT identify substances as acid, base, or neutral 2. SWBAT draw a pH scale and place substances on it according it's pH
3. SWBAT explain what happens during a neutralization reaction
4. SWBAT characterize household substances as acid, base, or neutral. 1
PH lab Honors p 6.notebook
September 23, 2014
pH Lab pH scale ranges from 1­14 and is a logarithmic scale.
Ex­ pH of 5 is 10x more acidic then a pH of 6 and 100x more then a pH of 7
I. Vocabulary:
A. Ion:
B. Dissociate: break into ions
C. Aqueous: relating to water
II. Pure Water
A. Dissociates:
B. # of ions:
III. Ions that pertain to acids/base
A. Hydrogen ions (H+)
B. Hydroxide ions (OH­)
IV. Acidic Solution: A. ions:
B. pH:
C. H2O= solvent, HCl = solute
H 2O
D. HCl H+ + Cl­
Let's Draw:
V. Basic Solution: A. ions:
B. pH:
C. H2O= solvent, NaCl = solute
H 2O
D. NaOH Na+ + OH­
Let's Draw!
Think ­ Pair ­ Share
1. What would happen to the H+ concentration if I added hydrochloric acid to the solution?
2. What about the pH?
2
PH lab Honors p 6.notebook
September 23, 2014
Do Now:
A can of cola consists of mostly sugar dissolved in water, with some carbon dioxide gas that makes it fizzy and makes the pH less than 7. In chemical terms....
A. The cola is an aqueous solution where the water is the ________.
B. The sugar is the ______________.
C. Carbon dioxide makes the solution ___________.
D. Explain the solution in terms of H+ and OH­. Objectives
1. SWBAT identify substances as acid, base, or neutral 2. SWBAT draw a pH scale and place substances on it according it's pH
3. SWBAT explain what happens during a neutralization reaction
4. SWBAT characterize household substances as acid, base, or neutral. pH Scale
1 2 3 | 4 5 6 | 7 | 8 9 10 | 11 12 13 14
measuring pH ­ Indicators
Litmus paper ­ Red
Blue
pH paper
3
PH lab Honors p 6.notebook
September 23, 2014
Do Now:
KOH + HF 1. Using the above equation, which reactant is the acid and which is the base?
2. What are the products?
3. When HF dissociates­ what is the cation? anion?
Objectives
1. SWBAT identify substances as acid, base, or neutral 2. SWBAT draw a pH scale and place substances on it according it's pH
3. SWBAT explain what happens during a neutralization reaction
4. SWBAT characterize household substances as acid, base, or neutral. Neutralization Reaction
NaOH + HCl H2O + NaCl 4
PH lab Honors p 6.notebook
September 23, 2014
Do Now:
Create a challenge question to ask a peer about the pH lab.
Analysis:
1. What is the possible range of pH values for all the solutions tested?
2. Which of the five substances you tested were acidic? How did you know using the Litmus paper?
3. Which of five substances you tested were basic? How did you know using the Litmus paper?
4. Were any substances neutral? How do you know?
5. Did the results using litmus pH paper agree with the results using the wide­range paper? Explain.
6. What additional information did the wide­range pH paper provide?
7. Compare the pH value and the color of the ammonia solution with phenolphthalein. What do these values tell about the solution? 8. Compare the initial pH value of the solution in Procedure B with the final pH value.
9. The objective of Procedure B was to demonstrate a neutralization reaction which produces a salt and water. Do the results you obtained in the neutralization investigation support the objective? Explain.
10. What do we know about our unknown substance? Provide data from our lab.
5
PH lab Honors p 6.notebook
September 23, 2014
Conclusion Questions: Are you ready for your lab quiz?
Grab a board, marker, and eraser!
1. Which substance is a stronger acid­ lemon juice (pH of 2) or tomato (pH of 4)?
3. What would happen to the OH­ concentration if I added sodium hydroxide to the solution?
4. What about the pH?
5. What are the products of a neutralization reaction? 6. What ions does HCl dissociate when dissolved in water?
7. How do you feel about pH? A, B, or C? 6