Download pH Scale Basics Remote Lab1 (1)

pH Scale Basics Remote Lab
(This lesson is designed for a student working remotely.)
This lab uses the pH Scale Basics simulation from PhET Interactive Simulations at University of
Colorado Boulder, under the CC-BY 4.0 license.
https://phet.colorado.edu/sims/html/ph-scale-basics/latest/ph-scale-basics_en.html
Learning Goals: Students will be able to:
● Determine if a solution is acidic or basic using pH.
● Relate liquid color to pH.
● Predict if dilution and volume will increase, decrease or not change the pH
● Organize a list of liquids in terms of acid or base strength in relative order with supporting
evidence.
Everyday Chemistry in your life:
1. List some common liquids that you think are acidic or basic. For example, do you think orange
juice is acid or base? Why do you think each liquid is an acid or base?
a. orange juice is ( Acid) and because its made of orange.
b. Coffee is a acid because its made of cocoa bean
c. Milk is a base because it doesn’t seem like an acid
d. . water is a base because its made of h20
e. . battery acid is a acid because its from a battery
2. Do you think the amount of the liquid changes how acidic or basic it is? Explain your thinking.
No because dilution affects the acidity and basicity of the liquid.
3. What do you think adding water (dilution) changes how acidic or basic the liquid is? Explain your
thinking. Yes I think it will change its pH level and make it more diluted.
Develop your understanding:
4. Use pH Scale Basics to test your ideas about some common things that are acids or bases.
4/10/20 Loeblein https://phet.colorado.edu/en/contributions/view/3183
page1
a. Describe your tests and results.
1. with no water orange juice is acidic and has a pH of 3.50, when you put water it stays acidic and
has a pH of 3.93
2. with no water coffee is acidic with a pH of 5.00, with water it stays acidic and has a pH of 5.53.
3. with no water milk is acidic and almost basic with a pH of 6.5, with water it stays as a acid with
6.7 pH
4. water stays basic with a pH of 7
5. with no water battery acid is an acid with a pH of 1, with water it stays a acid with 1.41 pH.
4. Experiment to check your ideas from #2 about how color or volume help identify whether
something is acid, base, or neutral. Describe your tests and results with specific examples.
When I put water into the substance the color would dilute into a shade of that color but either a
darker shade or a little light shade
5. Experiment to check your ideas from #3 about whether dilution will increase, decrease or
not change the pH.
a. Does every solution behave the same way: no the pH changes with more water or
more of the solution
b. Explain how you can use pH to help predict what dilution does to an acid or base
solution: you dilute the solution the pH goes down because the water is diluting the
acid or base
6. Consider some common drinks.
Alkaline water 8.0, Fruit juice 6.8, Gatorade 3.0, Green tea 9.0, Gatorade 3.0, Vinegar 3.5,
a. Organize this list of foods with pH from most basic to most acidic.
Green tea, alkaline water, fruit juice, vinegar, and Gatorade.
b. Which will have a higher pH if you dilute it with water?
Either the alkaline water or the green tea because the green tea already has water in it as well as
the alkaline water.
4/10/20 Loeblein https://phet.colorado.edu/en/contributions/view/3183
page2
Test your understanding and self-check: For each question, predict your answer and support
your answer with an explanation. Then use pH Scale Basics to verify and add screen captures to
your explanation.
1. Prediction and explanation with support
B false because the red acid (blood) is a base and the yellow is a acid.
2. Prediction and explanation with support
D. more than one because a is water b is blood and c is battery acid which is a acid.
3. Prediction and explanation with support
Increases the pH to 6.0 and more
4/10/20 Loeblein https://phet.colorado.edu/en/contributions/view/3183
page3
4. Prediction and explanation with support
B. lowers the pH when you put water in it
5. Prediction and explanation with support
A. ABC 6.50 is acid, 7.40 is a basic and 10.0 is a basic aswell.
4/10/20 Loeblein https://phet.colorado.edu/en/contributions/view/3183
page4