Blog 4.1 Fun With Air Pressure

Answer each of the following AND Explain!!! 

I am looking for you understanding of how and why the particles in the gases cause the change that you are predicting.

You will not receive full credit if you do not explain with complete sentences.

  

1. A decrease in pressure causes the volume of a balloon to _______________________.

                                                                                       (increase, decrease or stay the same?)

2. Adding more gas to a bottle ____________________ the pressure in that bottle.

                                                       (increases or decreases?)

3. As the volume of a cylinder is increased the pressure will __________________________.

                                                                                                    (increase, decrease or stay the same?)

4. Increasing the pressure in a tire by adding more gas will cause the volume to _______________ .

                                                           (increase, decrease or stay the same?)

5. As the temperature of a closed container of water is increased the amount of water vapor  above the water causes a(n) _________________________ in vapor pressure.

                                          (increase, decrease or no change?)

6. As the air pressure above a liquid is increased by adding more air, the boiling point of the liquid will _____________________.  (increase, decrease, or remain the same?)

7. If a balloon filled with air is taken under water to a depth of 10 feet, it’s volume will ______________________ . (increase, decrease, or remain the same?)

8. The temperature of a beaker of boiling water will __________________ as more heat is  added.                                                                                  (increase, decrease, or remain the same?)

  

9. Hot air rises because it is _____________ dense the cold air around it.  

                                                  (less or more?)

10.  When heated, the volume occupied by air in a balloon  will ___________________________ .

                       (increase, decrease or stay the same?)

Tell whether each of your predictions was accurate or not. This should take at least four sentences in order to say if you were correct, and then why or why not.

ENRICHMENT: 

Try to explain what happened to the tanker car shown in the pix, in terms of gas particle behavior.  The situation happened when some workers cleaned the tanker out with a hot water flush and then sealed the tanker car lid after doing their work in the middle of the day.  That night, the air temperature dropped down to the 35⁰F range.  The car did this sometime during the night.

Blog 3.2 Properties of Ionic and Covalent Compounds

Conclusion:

 Respond to each item asked for on the rubric and answer the following questions.

1. List the general properties of ionic compounds. (hardness? conductivity? conductivity in solution? melting point?)

 

2. List the general properties of covalent substances. (hardness? conductivity? conductivity in solution? melting point?)

 

3. What types of elements combine to form ionic bonds? Explain what happens with electrons with this type of bonding.

 

4. What types of elements combine to form covalent bonds? Explain what happens with electrons with this type of bonding.

5. Why do covalent compounds lack the ability to conduct electricity as a solid or in solution?

 

6. Why do ionic substances conduct electricity in solution, but not as solids?

Enrichment:

Solutions containing ions are often called “electrolyte solutions.”  Research electrolytes and find out:

¨  Why drinks like Gatorade advertise that they contain electrolytes,

¨  What electrolytes have to do with you and exercising,

¨  How electrolytes are used by your body to transmit messages from your brain to your muscles,

¨  What is the electrolyte substance used by your body?

Lab 3.1 Modeling of Molecules

As we know, all matter is made up of little particles. 

When a sample of material is known to use covalent bonds, the material is said to be “molecular,” or in other words, the material is made up of “molecules.”  A cluster of HCl molecules is shown below.  Molecules have an electrical charge of zero.

 

 

When a sample of matter is known to use ionic bonds, the material is said to be “ionic,” or in other words, the material is made up of “ions.”  A cluster of Al³⁺ and O^2- ions is shown below.  Ions have electrical charges on them.

 

One way of knowing whether a material is using ionic or covalent bonds is to test its melting point.  It is generally true that molecular substances have lower melting points than ionic substances.  For example, HCl melts at -115^oC while Al₂O₃ melts at 2072^oC. 

1.  Decide whether you think the attraction between ions is stronger than between molecules, or visa-versa.  Explain what evidence you are using from the information above, in order to make a conclusion about this.

2.   When HCl molecules are melted, do we still have HCl molecules, or are the molecules broken down into H and Cl atoms?  Explain based on your understanding of whether the process of melting is a physical or chemical change.

3.  When ionic substances are melted, they can conduct electricity.  When they are solids, they can not.  Explain why this is so.

4.  Molecular substances do not conduct electricity in either solid or liquid form.  Why not?

ENRICHMENT:  Research what a “polar” molecule is.  Find out whether or not water molecules are polar.  Draw a set of 4-5 water molecules showing how they arrange when touching each other.

Blog 2.2 Bag of Ions and Periodic Table Activities

After completing these activities I am looking for you guys to communicate your understanding for the organization for the periodic table. So please consider the following [Bill Nye Reference]

PARAGRAPH ONE: In your own words describe how the periodic table is arranged, you may wish to include something about the groups and periods, electron configuration, valence electrons, and the different families.

PARAGRAPH 2: For the second part, I want you to compare and contrast ions and atoms:

• What is similar about atoms and ions of the same element
• What is different about atoms and ions of the same element
• Why do ions form?
• How can you predict the charge on an ion by looking at valence electrons and location on the periodic table

Overall, I am looking for how well you understand these concepts, if you have any questions use your packets and notes and chem crunches, and don't be afraid to ask questions!!

Lab 2.1 Grouping of Elements [Due Friday 10/21]

Lab 2.1 Grouping of Elements

1.    Based on the information in your text on p158-160 (or your reading you completed for homework),  “Name” the groupings of elements that you created on the last page of the lab.

2.  Classify the four properties tested in this lab as either a physical property or chemical property.  Explain your thinking.

3.   a)  State what is unique about elements that are “metalloids.” 

b)  Identify any elements among our seven that are metalloids.

c)  List the names and symbols of all the metalloids. 

4.   When you look at a Periodic Table, you will notice that the seven elements we tested are all clustered near each other. 

State the trend that appears to exist:

a)  In terms of metallic character of elements, as you proceed from elements on the left to elements on the right in the Periodic Table.

b)  In terms of metallic character of elements, as you proceed from elements near the top to elements near the bottom in the Periodic Table.

ENRICHMENT:  Some elements, like lead (Pb), have symbols that due not seem to match their names.  Pb is derived from the Latin name for lead, which is “plumbum.”  This is due to the fact that this element was used in Roman times for making pipes for drinking water (“plumb”ing pipes).  There are 10 other elements like this.  Find one or more of them, and research why the symbol is what it is.

LAB 1-3 Separation of a Mixture [Due Wed 9/28]

Hey Everyone, from reading your blogs it looks like you are getting the idea for the general outline and purpose of what we are trying to accomplish with the blog. If there are some comments asking you to add to your blog or edit it, please make the changes, your grade will reflect it.

For this experiment you need to write the normal paragraph summary outlining what you did. After you do that you need to consider the following:

1. Compare the amounts of iron, sand and salt that you had initially in your mixture to the amounts that you recovered. Were they all equal? Propose a reason for each of them being different than expected. I won't accept reasons stating that you measured wrong or did math incorrectly. I am looking for problems with the experiment.

2. How could you have made your separation better? For example: if you had sand left in your iron what could you have done to get it out?

Write a conclusion paragraph explaining how what we did relates to what we are currently doing in class. If you have further questions, this would be the place to ask the questions and address what happened.

Enrichment: Do a little research and find out the steps that are used to manufacture and purify a chemical. The important process here is the purification, because it directly relates to what we are doing in class.

Lab 1-1 Green Stuff [Blog Due Friday 9/23]

Ok, now you have completed your first experiment and have had a little bit of a chance to think about it.

The purpose of the lab blog is to do the thought processing that goes along with the experiences that you had in the experiment.

Your blog post should be outlined as follows:

• A quick summary of the experiment, tell me what you did (a procedure) and what happened (your results). I am usually looking for roughly a paragraph here, you need to provide enough so that I can tell that you understood what you were doing.
• Answers to the lab questions, in this case they are:
• Explain how you can determine if a property of green stuff is a physical property, or a chemical property.
• Describe the different phases of matter of the chemicals (water is a chemical too) used in this experiment. Make sure to tell how solids, liquids and gases are different.

•  Describe how the material relates to what we have been completing in class. Also this is where you can pose questions that the lab made you think about, I like to see this stuff and respond to it.
• Enrichment Questions: I will at times pose enrichment questions, if you want to get 5/5 on all categories all the time, you will need to answer these. For this experiment, come up with an experiment that you would like to try with green stuff. Its name is copper (II) chloride if you want to do a search.