Equilibrium: Weak and Strong Acids
use this recitation to make connections among the concepts of strength, concentration, and pH.
Part I: You Initial Ideas
Answer the following True/False questions for yourself. Then check in with your group. You dont all have to agree- just get a sense of what others are thinking. You will re-evaluate your answers at the end of recitation, so it's okay to be unsure at this point.
1. Strong acids completely dissociate in water - sometimes true
2.Strong acides have lower pH's than weak acids-always true
3. A ten fold dilution of a strong acidic solution will decrease the pH by 1. - always true
4. A solution with H3O=0.01 M contains a stronger acid than a solution with H3O =0.001M.-Always false
5. A solution whose pH is 2.00 contains a stronger acid than a solution whose pH is 3.00- Sometimes true
Part II: Strong and Weak Acids
Open the simulation on your computer. Ust the 1st tabe to explore how storng and weak acids differ.
1. A strong acid is one which is virtually 100 % ionised in solution
2. A weak acid is one which doesnt ionise fully when it is dissolved in water.
Tuesday, July 5, 2011
Activity 7
1. There are 2 balloons in a room. They are identical in size and material. One balloon is filled with air and the other balloon is filled with Helium. How does the pressure of the air balloon compare to the pressure of the Helium balloon. The pressure in the air balloon is
Less 2. How does the pressure in the Helium balloon compare to the pressure of the air in the room? The pressure in the Helium balloon is
Greater
3. How do the number of air molecules in the air balloon compare to the number of He atoms in Helium balloon?
The number of air molecules is
The number of air molecules is
Less
4. How does the average speed of the Helium molecules compare to that of the air molecules?
The average speed of the He molecules is
The average speed of the He molecules is
Greater
5. What will happen to the pressure if temp is held constant and the volume is decreased?
Pressure goes up because more collisions are happending, but same force per collision
6. You are flying from Denver to Boston, and you bring along a ½ full bottle of shampoo that was well sealed before you left Denver. You land in Boston and proceed to your hotel. The number of air molecules within the shampoo bottle:
Has increased
7. If the walls of the shampoo bottle are strong and rigid so that the bottle has the same shape as before you left, how does the pressure of the air inside the bottle compare to the pressure of the air in Denver?
Greater than
8. How does the pressure inside the bottle compare to the pressure of the air in Boston?
Greater than
9. If you had a water bottle with very soft sides. When you open your suitcase in Boston, the bottle would look
Puffed out
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 | 7.0 |
pH paper (color) | red | orange | blue | green | yellow |
Conductivity (bright/dim/none) | bright | dim | bright | dim | none |
Exists as Mostly (ions/molecules) | ions | molecules | ions | molecules | molecules |
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 :__4.0_______ Strong Acid, 0.01 M :__2.0_______
Activity 6
32 F=273 Kelvin
70 F=294.111 Kelvin
212 F=373 Kelvin
2.
3. When the water had started to cool the molecules began to slow down were at one point they were barely even moving.
4. Temperature-589 K
Pressure- 63 ATM
5.
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-This I feel we did alot throughout this activity we had to look at many different models and explain what was taking place.
A.4.3 When investigating a science-related problem, decide what data can be collected to determine the most useful explanations
-We collected alot of data throughout this activity it is sort of like my other explanation we had to observe alot, draw, and explain what was taking place in the photos.
Activity 5
The equation of denisty is:
Density=Mass/Volume
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
B.4.1 Use encyclopedias, source books, texts, computers, teachers, parents, other adults, journals, popular press, and various other sources, to help answer science-related questions and plan investigations
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
D.4.5 Construct simple models of what is happening to materials and substances undergoing change, using simple instruments or tools to aid observations and collect data
G.4.3 Determine what science discoveries have led to changes in technologies that are being used in the workplace by someone employed locally
Activity 4
Standard A:
A.4.1 When conducting science investigations, ask and answer questions that will help decide the general areas of science being addressed
For standard A I have experianced this recently with our first activity. A.4.1 says when conducting science investigations, ask and answer questions that will help decide the general areas of science being addressed. So with our first experiment some of our questions that we had were does warm or cold water freeze faster? Also, does warm or cold water boil faster? After doing the experiment we had the answers for this question.
Standard B:
B.4.1 Use encyclopedias, source books, texts, computers, teachers, parents, other adults, journals, popular press, and various other sources, to help answer science-related questions and plan investigations
I feel that standard B has to do with my everyday life whether I am in school, working or at home. Basically, standard be is saying you now know how to use different sources such as internet, adults, encylopedias, ext. I use different resources everyday for various things. As I got older I became more aware of different resources and became better at them such as how to use the internet. I think it is very imporant for everyone to be aware of the different kinds of resources that are out there for us, and how important it is for everyone to know how to use them.
Standard C:
C.4.6 Communicate the results of their investigations in ways their audiences will understand by using charts, graphs, drawings, written descriptions, and various other means, to display their answers
I think with this standard it has alot to do with how to read different charts, graphs, tables ext. With any kind of science it is very imporant to know the correct wording of things. I think that it is important to know things from the periodic table and the basics of what things are and symbols. An example would be like H20 for water. Its important to know the basics and correct wording of things.
Standard D:
D.4.1 Understand that objects are made of more than one substance, by observing, describing and measuring the properties of earth materials, including properties of size, weight, shape, color, temperature, and the ability to react with other substances
I have experianced this also by this class. In this class we have had to work alot with the periodic table. We also became aware of what things are in which of the groups for the tables. We know that chemicals can be solid, liquids, or even gases. Also, there are seven different groups in the periodic table that we have had to come some what familiar with.
Standard E:
E.4.1 Investigate that earth materials are composed of rocks and soils and correctly use the vocabulary for rocks, minerals, and soils during these investigations
This standard has alot to do with the earth and rocks. I have become familiar with rocks many years ago. For my fifth grade science fair my project had to do with the different kinds of rocks that there are. Besides putting the different rocks in their proper group I had also had to find and identify many different rocks. This can be alot more difficult than you may expect, because there are many different things you need to look at with rocks.
Standard F:
F.4.1 Discover* how each organism meets its basic needs for water, nutrients, protection, and energy* in order to survive
Throughout my many years of being in school I have seen many different videos about what different kinds of animals do to survive. It has alot to do with the environment that they are in because many animals learn to adjust to their environment and that is how they survive. You also have to look at what they eat and the different kinds of food that is available for them in the area that they are living in.
Standard G:
G.4.1 Identify* the technology used by someone employed in a job or position in Wisconsin and explain* how the technology helps
We see technology growing all around us. For being a early childhood major we see alot of the interactive whiteboards that are growing in the classrooms that give the children and also the teacher many different opportunities to help make things more exciting for the children. Also, technology in the workplace just recently I had started a new job, and instead of going in and filling out a paper form of an application I was suppose to go online and fill it out on the computer. I have learned that this is the way that many places are now doing.
Standard H:
H.4.1 Describe* how science and technology have helped, and in some cases hindered, progress in providing better food, more rapid information, quicker and safer transportation, and more effective health care
We see transportation all around us. However, in my hometown, which is very small, minonights are very common so often when you are driving you will see a horse and buggy going down the road. This is just one example at how we have imporved with transportation. Also, people are able to fly so much now to save time. Some trips would take days to drive some where, and now you are able to be there in a couple of hours. Its really amazing to see how things have imporved.
A.4.1 When conducting science investigations, ask and answer questions that will help decide the general areas of science being addressed
For standard A I have experianced this recently with our first activity. A.4.1 says when conducting science investigations, ask and answer questions that will help decide the general areas of science being addressed. So with our first experiment some of our questions that we had were does warm or cold water freeze faster? Also, does warm or cold water boil faster? After doing the experiment we had the answers for this question.
Standard B:
B.4.1 Use encyclopedias, source books, texts, computers, teachers, parents, other adults, journals, popular press, and various other sources, to help answer science-related questions and plan investigations
I feel that standard B has to do with my everyday life whether I am in school, working or at home. Basically, standard be is saying you now know how to use different sources such as internet, adults, encylopedias, ext. I use different resources everyday for various things. As I got older I became more aware of different resources and became better at them such as how to use the internet. I think it is very imporant for everyone to be aware of the different kinds of resources that are out there for us, and how important it is for everyone to know how to use them.
Standard C:
C.4.6 Communicate the results of their investigations in ways their audiences will understand by using charts, graphs, drawings, written descriptions, and various other means, to display their answers
I think with this standard it has alot to do with how to read different charts, graphs, tables ext. With any kind of science it is very imporant to know the correct wording of things. I think that it is important to know things from the periodic table and the basics of what things are and symbols. An example would be like H20 for water. Its important to know the basics and correct wording of things.
Standard D:
D.4.1 Understand that objects are made of more than one substance, by observing, describing and measuring the properties of earth materials, including properties of size, weight, shape, color, temperature, and the ability to react with other substances
I have experianced this also by this class. In this class we have had to work alot with the periodic table. We also became aware of what things are in which of the groups for the tables. We know that chemicals can be solid, liquids, or even gases. Also, there are seven different groups in the periodic table that we have had to come some what familiar with.
Standard E:
E.4.1 Investigate that earth materials are composed of rocks and soils and correctly use the vocabulary for rocks, minerals, and soils during these investigations
This standard has alot to do with the earth and rocks. I have become familiar with rocks many years ago. For my fifth grade science fair my project had to do with the different kinds of rocks that there are. Besides putting the different rocks in their proper group I had also had to find and identify many different rocks. This can be alot more difficult than you may expect, because there are many different things you need to look at with rocks.
Standard F:
F.4.1 Discover* how each organism meets its basic needs for water, nutrients, protection, and energy* in order to survive
Throughout my many years of being in school I have seen many different videos about what different kinds of animals do to survive. It has alot to do with the environment that they are in because many animals learn to adjust to their environment and that is how they survive. You also have to look at what they eat and the different kinds of food that is available for them in the area that they are living in.
Standard G:
G.4.1 Identify* the technology used by someone employed in a job or position in Wisconsin and explain* how the technology helps
We see technology growing all around us. For being a early childhood major we see alot of the interactive whiteboards that are growing in the classrooms that give the children and also the teacher many different opportunities to help make things more exciting for the children. Also, technology in the workplace just recently I had started a new job, and instead of going in and filling out a paper form of an application I was suppose to go online and fill it out on the computer. I have learned that this is the way that many places are now doing.
Standard H:
H.4.1 Describe* how science and technology have helped, and in some cases hindered, progress in providing better food, more rapid information, quicker and safer transportation, and more effective health care
We see transportation all around us. However, in my hometown, which is very small, minonights are very common so often when you are driving you will see a horse and buggy going down the road. This is just one example at how we have imporved with transportation. Also, people are able to fly so much now to save time. Some trips would take days to drive some where, and now you are able to be there in a couple of hours. Its really amazing to see how things have imporved.
Tuesday, June 28, 2011
Activity 3
IUPAC: Gold
My homemade molecule
My homemade molecule
IUPAC:Methane
My homemade molecule
20 Chemicals that we use:
water-oxidane
oragne juice-citric acid
wheat-hydrolyzed starch
plastic-polyethylene
corn-fructose
leather-xylene
salt-magnesium sulfate
chalk-calcium carbonate
diamonds-carbon crystal
vitamine c-ascorbic acid
butter-butanoic acid
potatoe chips- olestra
nails-iron
pop cans-aluminum
air-oxygen
pennies-copper
vinegar-impure dilute acetic acid
matches-phosperous
watch batteries-litium
pencils-graphite
IUPAC means:
International Union of Pure and Applied Chemistry
Some companies claim to be safe; however, they get away with this because they do not use as harsh chemicals as some companies may such as amonia.
Activity 2
Carbon- when paper burns it creates carbon
Copper- We find copper in our everyday lives in pennies
Aluminum- We find in pop cans and of course aluminum foil
1. What is the atomic number for each of your models?
a. Carbon- 6
b. Copper-29
c. Aluminum-13
2. What is the atomic mass number for each of your models?
a. Carbon- 12.0107
b. Copper-63.546
c. Aluminum-26.981538
3. In your models, which two subatomic particles are equal in number?
a. Non are
4. How would you make an isotope for one of your models? What would change with the model?
a. Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons.
5. Considering the overall volume of your element models, what makes up most of the volume of an atom?
a. It is mostly filled with nothing. There is a central heavy nucleus and “whizzing’ round it are a number of much lighter much smaller electrons. From the outermost reaches of the electrons orbits to the centre of the nucleus there is an awful of nothing in it.
6. Show with another image what happens when energy excites an electron.
7. Once the electron is excited, what do we typically observe when the electron returns to the ground-state?
8.Why are some elements different colors when they are excited?
a. The color emitted depends on the amount of energy released.
a. The colors of fireworks are determined by the minerals placed inside the shell along with the explosive charges - for example, strontium produces a red color. For the sparkling, they include aluminum shavings. See the links below and click through on some of the articles for more information.
9. With the Fourth of July coming up quickly, explain how the colors of fireworks arise.a. The colors of fireworks are determined by the minerals placed inside the shell along with the explosive charges - for example, strontium produces a red color. For the sparkling, they include aluminum shavings. See the links below and click through on some of the articles for more information.
Source(s):
10. Explain the overall organizational structure of the periodic table.
a. Elements are listed in order of increasing atomic number. Rows are arranged os that elements with similar properties fall into the same columns.
11. List two example elements for each of these groups or classes: Alkali Metals, Alkaline Earth, Halogens, Noble Gases, Transition Metals, Non-Metals, and Metalloids.
- Alkaline Metals-Sodium
- Alkaline Earth- Magnesium
- Halogens- Chlorine
- Noble Gases- Neon
- Transition Metals- Iron
- Non Metals- Hydrogen
- Metalloids- Boron
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