Activity 8

1. Choose any Teaching Idea from any of the Chemistry Simulations (http://phet.colorado.edu/en/simulations/category/chemistry ) and post your results/data and/or answers on your blog.

Build an Molecule- Concept Questions

By Patricia Loeblein

(http://phet.colorado.edu/en/contributions/view/3434)

       1. Which picture best displays atoms?
                A.,  B.,   C. Both would be described as “atoms”,  or  D. Both are better described as molecules
                Answer: A
        2. Which picture displays 2NH3?
                A.,  B.,  C.,  or  D. Two are correct
                Answer: D, both B and C
         3. Which could be hydrochloric acid?
                A.,  B.,  C.,  or  D. Two are correct
                Answer: A only if it is in a water solution.
          4. Which could be CO2?
                A.,  B.,  C. Both are stable
                Answer: B
          5. What is the name of this molecule?
                A. Methane,  B. Tetrahydrogen carbide,  C. Ammonia,  or  D. Water
                Answer: A Methane
          6. What is the name of this molecule? 
                A. Dihydrogen oxid,  B. Carbon dioxide,  C. Ammonia,  or  D. Water 
                Answer: D. Water
           7. What is the name of this molecule?
                A. Dichloride,  B. Dichlorine,  C. Chlorine,  or  D. This is not a stable molecule
                Answer: C. Chlorine


2. Work with any of the Chemistry Simulations to create your own Teaching Idea. The criteria for this is as follows:
a. must identify and meet three (3) science education standards
b. must be original work
c. must be scientifically accurate and appropriate for the directed grade level.

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Name:____________________________                     Date:_____________

Microwaves

Looking at how a microwave heats up food. 3^rd Grade Students

Science Standards:

A.4.1 When conducting science investigations, ask and answer questions that will help decide the general areas of science being addressed

A.4.2 When faced with a science-related problem, decide what evidence, models, or explanations previously studied can be used to better understand what is happening now

C.4.1 Use the vocabulary of the unifying themes to ask questions about objects, organisms, and events being studied

C.4.2 Use the science content being learned to ask questions, plan investigations, make observations, make predictions, and offer explanations

Set the simulation to: Single Line of Molecules with the Field View on Curve

1.     1. Set the amplitude at 0.05 draw a picture of what happens:

2.  Press the reset button and set the amplitude at 0.25, do the water molecules move faster or slower? ___________________

3.    Press reset and set the amplitude at 0.25 and the frequency at 0.00300, do the water molecules move faster or slower than the time before?_____________

4.    Play with the amplitude raising it an lowering it does lowering the amplitude make the water molecules move faster or slower?____________________

5.    Use the simulation to test if raising and lowering the frequency will make the water molecules move faster or slower, and write a sentence telling what you found….______________________________________________________________________________________________________________________________________________________________________________________________________________________________

6.   When the water molecules move faster in the microwave that means the temperature is raising or lowering?___________________

Activity 7

1. Review the Content Slides Acids and Bases on the D2L site.
2. Complete the Teaching Idea “Concept Questions for Chemistry using PhET”  posted by Trish Loeblein on the pH Scale simulation at PHET (http://phet.colorado.edu/en/simulation/ph-scale). On your blog post the answers with your scientific explanations from the “Clicker Questions pH Scale” posted by Trish.
      1. The color of a solution identifies if it is an acid, base, or neutral solution
             A.True   B. False   C. Pink are base and clear are acid
             B  Show sim: the left is milk, then blood, then a custom liquid like NaOH

      2. Which solution is basic?

             A,  B,  C,   D(more than one), or  E(None)
             D (B and C)  A milk, B blood  C. custom at pH =12

       3. Which solution is acidic?
             A,   B,   C,  D(More than one,   or E(Difficult to tell)
             C, but they may argue E    A. Custom pH =13  B. water pH =7  C. vomit pH=2

        4. Which solution is basic?

             A,  B,  C,   D(more than one), or  E(None)

             B   A. Water pH =7 B. pH =13  C. soda pop pH =2.5

        5. Which solution is acidic?

             A,  B,  C,   D(more than one), or  E(None)

             D (A and B) A. Coffee pH =5 B. soda pop pH =2.5 C. custom pH =13

        6. How will adding water effect the pH?
              A.Increase the pH,  B.Decrease the pH, or C.No pH change
              A more water lessens the acidity, so pH goes up
        7. How will equal amount of water effect the pH?
              A.Increase the pH,   B.Decrease the pH,  C.The pH will be cut in half,  D.No pH change 
              B: more water lessens the basicity , so pH goes down, but not by 2 (log scale)

         8. What is the order from most acidic to most basic?
              A.A B C,  B.A C B,  C.B A C,  D.C B A,  or  E.C A B
              A:  A milk, B blood  C. custom at pH =12
         9. What is the order from most acidic to most basic? 
               A.A B C,  B.A C B,  C.B A C,  D.C B A,  or  E.C A B
               C   A. Water pH =7 B. pH =13  C. soda pop pH =2.5
          10. If spit has a pH = 7.4, what does that  tell you about the water equilibrium?
           2H2O « OH-  + H3O+ 

                A.Something was added that made the equilibrium shift left

                B.Something was added that made the equilibrium shift right

                C.pH has nothing to do with the water equilibrium

                A: Since the pH is not 7, then something was added to make the equilibrium shift left. For example, if NaOH was added to water, OH- is immediately in the solution and some of it will react with the H3O+  , so the pH (which is inversely related to [H3O+ ]), goes up. 

                   If something like HCl were added there would be more H3O+ , which would also cause a shift

                   left, but there would be less OH- , (which is directly related to pH), so the pH is less than 7.

3. Complete the Teaching Idea “Intro to Strong and Weak Acids and Bases” posted by Chris Bires on the Acid-Base Solutions simulation (http://phet.colorado.edu/en/simulation/acid-base-solutions) and post on your blog your data and answers to the questions posed.

	Strong Acid	Weak Acid	Strong Base	Weak Base	Water
pH meter read (value)	2	4.5	12	9.5	7
pH paper (color)	Red 2	Orange 4	Blue 13	Grey 9	Yellow 7
Conductivity (bright/dim/none)	Bright	Dim	Bright	Dim	None
Exists as Mostly (ions/molecules)	Molecules	Molecules	Molecules	Molecules	Molecules

Strong Acids

Strength	Initial Acid Concentration (mol/L)	[HA] (mol/L)	[A-] (mol/L)	[H+] (mol/L)	pH
	.010 M	negligible	100x10-2	100x10-2	2
	.050 M	negligible	5.00x10-2	5.00x10-2	1.3
	.100 M	negligible	1.00x10-1	1.00x10-1	1
	1.00 M	negligible	1.00x10 0	1.00x10 0	0

Weak Acids

Strength (approximately)	Initial Acid Concentration (mol/L)	[HA] (mol/L)	[A-] (mol/L)	[H+] (mol/L)	pH
	.015 M	1.54x10-2	3.92x10-5	3.92x10-5	4.41
	.150 M	1.50x10-1	1.22x10-4	1.22x10-4	3.91
	.015 M	1.51x10-4	1.48x10-2	1.48x10-2	1.83
	.150 M	1.29x10-2	1.37x10-1	1.37x10-1	.86

Strong Bases

Strength	Initial Acid Concentration (mol/L)	[MOH] (mol/L)	[M+] (mol/L)	[OH-] (mol/L)	pH
	.010 M	negligible	1.00x10-2	1.00x10-2	12
	.050 M	negligible	5.00x10-2	5.00x10-2	12.70
	.100 M	negligible	1.00x10-1	1.00x10-1	13
	1.00 M	negligible	1.00x10 0	1.00x10 0	14

Weak Bases

Strength (approximately)	Initial Acid Concentration (mol/L)	[B] (mol/L)	[BH+] (mol/L)	[OH-] (mol/L)	pH
	.015 M	1.50x10-2	3.87x10-5	3.87x10-5	9.59
	.150 M	1.50x10-1	1.22x10-4	1.22x10-4	10.09
	.015 M	1.51x10-4	1.48x10-2	1.48x10-2	12.17
	.150 M	1.29x10-2	1.37x10-1	1.37x10-1	13.14

Conclusion Questions:

1.      A strong acid is very concentrated / exists primarily as ions. (circle)

2.      A weak base is a nonelectrolyte / weak electrolyte / strong electrolyte.

3.      A strong base is a nonelectrolyte / weak electrolyte / strong electrolyte.

4.      At the same concentration (Molarity) a strong acid will have a higher / lower / the same pH as a weak acid.

5.      As concentration of a weak acid increases, the pH increases / decreases / remains constant.

6.      As concentration of a weak base increases, the pH increases / decreases / remains constant.

7.      As the concentration of a weak acid increases, the number of ions increases / decreases / remains constant.

8.      As the concentration of a weak acid increases, conductivity increases / decreases / remains constant.

9.      As the strength of a weak acid increases, the proportion of ions to molecules increases / decreases.

10.  As the strength of a weak acid increases, the conductivity increases / decreases / remains constant.

11.  What are the pH values of a weak acid with a concentration of 0.10 and a strong acid with a concentration of 0.01, ten times lower?     Weak acid, 0.10 M :  4.35       Strong Acid, 0.01 M :   1.00