Properties and Physical and Chemical Changes of Matter

8/29/13 Scribe Post Author: Juliette O.

Class on 8/29/13    

8/28/13 Homework Check 

In the beginning of class, Ms. Friedmann checked in everyone's homework from Wednesday, 8/28/13. The homework due today was the WebAssigns on Chapter 1: 1.1 and 1.2, the notes on the ChemThink Particulate Nature of Matter Tutorial and quiz questions, and the two Particulate Nature of Matter green sheets in the composition notebook. 

After checking in the homework, Mrs. Friedmann addressed questions about the Internet activities (WebAssign and ChemThink), and then we went over the green Particulate Nature of Matter worksheets and the blue Paper Clip activity in our composition notebook. We then took a quiz on Section 1.1 in the book. We took notes on the second and third Questions for Today.

If you were absent today, you are responsible for showing Mrs. Friedmann the homework that was due today and checked in today. You are also responsible for taking the quiz in the Test Center.

Questions for Today:

How comfortable do you feel with telling the difference between:

--elements and compounds

--mixtures and pure substances

--atoms and molecules?

·      What is the difference between a property and a change?

·      How is physical different from chemical? 

Questions about Web Assign and ChemThink

First, some people reported to Ms. Friedmann that there were glitches in WebAssign or ChemThink. Her tips:

•  If there is a glitch, notify Ms. Friedmann with an email and, if possible, a screenshot of the problem.
• Don't get hung up on the glitch; try to complete the assignment, but if you have a problem make sure to talk to Ms. Friedmann and let her know about it.

Second, WebAssigns, no matter what number of points they were out of online or how many questions, are always out of 10 points.  Whatever percentage you got on the assignment is taken out of those 10 points.

Third, sometimes Mrs. Friedmann will assign a WebAssign on a topic that we have not learned yet, so the lesson the next day is review.

 Mrs. Friedmann also reminded us that we should always check the Chemistry Blog, Moodle page and Daily Homework Log each night!

Homework Check

 Paper Clip Activity

We went over the paper clip activity in class today. 

Examples:

1) Sample # 3: 3 Jb

This sample has 0 molecules because each atom of Jb is individual. The coefficient 3 shows that there are 3 individual atoms of Jb. If the formula looked like Jbsubscript 3, there would be 1 molecule, because the subscript 3 means there is a molecule made up of 3 atoms.

2) 2 Sm3 + JbCl2

The plus sign shows us that this is a mixture. 2Sm3 is a polyatomic element, because each atom is the same element and there are many atoms in the molecule. JbCl2 is a compound, because there is more than one element.

Notes to Consider:

• ·      If there is only 1 kind of element (such as 3Jb) in the sample, then it is an element.
• ·      The + sign implies that there is a mixture; no + implies a pure substance.
• ·      Pure substance: all the smallest individual pieces are the same
• ·      Homogenous Mix: Same throughout (blood)
• ·      Heterogenous Mix: Different throughout (fruit salad, medicine you shake)

Particulate Nature of Matter Worksheets

We went over the worksheets in class.  

Notes to Consider:

• ·      A compound is always a molecule, but a molecule is not always a compound.
• ·   Allotrope: each of two or more different physical forms in which an element can exist. (Element that exists as monatomic, diatomic and polyatomic)

• Ex: there are many different kinds (allotropes) of carbon-- bucky balls, carbon nanotubes, diamond, graphite in pencil. Nanotech uses carbon allotropes. 

·      When describing pictures of a sample of matter or a formula, ask yourself:

·      Atom or molecule?

·      Mixture or Pure Substance?

·      Element or Compound?

Quiz on Section 1.1

We had a short quiz on Section 1.1 in the textbook. If you were absent, you should make up the quiz in the Test Center.

Notes: 

Properties versus Changes 

Property: A substances potential to change. 

• The ability to:
• react with an acid
• melt at 50 degrees celsius ("melting point")

Change: A before and after. 

• The actual process of:
• reacting with an acid
• melting 

Physical Changes vs. Chemical Changes

Physical Change: The identity of the substance stays the same

Chemical Change: The identity of the substance changes.

To get to notes, go to GBS moodle. Click on Chemistry Honors 173  Friedmann, and go under Resources to Unit 1 Handouts. Under Unit 1 Handouts, there should be a link to 8/29 Notes on Chemical and Physical Changes. 

Thursday, 8/29 Homework

1) WebAssign 1.2 -- Measurement and Sig Figs.  Due Saturday night by 11:59 pm.  A friendly suggestion:  plan your weekend accordingly!  Since you have no other homework for now, I strongly suggest you work on this assignment tonight.  You do not need to finish WebAssigns all in one sitting; you can save your work and come back to it later.  If you choose to do this, however, do not forget about your Saturday night deadline as you enjoy Friday and Saturday!

2) We took a quiz on section 1.1 of the text today.  If you were absent, please make it up in the test center when you return.

The next scribe post author is Katie Coy. 

Introduction to ChemThink & Paper Clip Activity

8.28.13 Scribe Post Author: Ekene N.

8.27.13 Homework Check

In the beginning of class, Mrs. Friedmann checked everyone's homework from last night. The correct answer to the assignment was:

"HETEROGENEOUS MIXTURE." Your explanation should have been close to at least one of the following:

• Not all parts of the taco salad mixture would have contained the same overall makeup, therefore the salad is a is a heterogeneous mixture.
• One part of the taco salad will have different contents than another part.
• In one part of the salad, there may be more of one single ingredient (ex: shredded cheese) than in another part of the salad.

Taco salad...it is perfectly normal if you are 
currently craving some taco salad right now :)

Introduction to ChemThink

Today, we registered for an online program called ChemThink. If you were absent, we received a handout that obtains the instructions that will guide you through the process of registering for this website.You can access a copy of the handout by clicking the link below. (If the link doesn't work, go on Moodle...Unit 1 Handouts...8.28_ChemThink_Registration_Directions.pdf)

http://gbs-moodle.glenbrook225.org/moodle/file.php/12015/1314_Unit_1/Unit_1_Handouts/8.28_ChemThink_Registration_Directions.pdf

*NOTE: The code you need to create your own account is valid until September 11. Again, if you were absent, try to access the pdf with the instructions ASAP.

Paper Clip Activity

For the majority of class, we did an activity that involved paper clips, which are in fact the newest elements that were just discovered yesterday ;) . The paper clips represented different atoms. If you were absent today, you are responsible for printing out the activity on Moodle (under Unit 1 Labs & Activities) and completing it on your own.

    A Couple Notes to Consider about the Activity:

• Molecules= clumps of atoms (they could be the same atoms or different ones)

• One paper clip hooked to another paper clip= chemically combined atoms

• If there is a plus sign found in the formula of sample=  physically combined atoms & mixture

• The coefficient in front of a sample (ex: 2Sm2), is the number of molecules.

• The subscript [ex: Sm(3)], is the number of atoms

Homework

•  Read sections 1.1 and 1.2 in your textbook.  WebAssigns 1.1 and 1.2 are due tonight by 11:59 pm.

• Log onto ChemThink and complete the Particulate Nature of Matter tutorial AND quiz.  As you complete the tutorial, take notes in your journal.  Due tonight by 11:59 pm.

•  Particulate Nature of Matter worksheet (in the Unit 1 Handouts folder).  Due tomorrow.

*NOTE ABOUT HW: Mrs. Friedmann said that the homework assigned for tonight may seem heavy in voluminous terms. However, the homework assigned for tonight is not heavy in content because the concepts in the homework aren't as challenging. Make sure to get the web assignments in before 11:59!

Other Important Information

• It is important to make sure you understand all of the concepts we have learned so far because there is an in-class quiz tomorrow.
• Mrs. Friedmann said that if you complete the assigned readings, the WebAssigns, and tonight's homework, you are already preparing yourself for the quiz.
• If you were absent, Mrs. Friedmann will check your Paper Clip Activity answers tomorrow.

A sample of the Paper Clip Activity 

The next scribe post author is: Juliette Ovadia

      

Introduction to Matter

Scribe post by: Ambreen A.
Overview
Today we started off class of by sharing our opinions about the Observation Lab, then took a small quiz on Independent and Dependent variables. In addition, Mrs. Friedmann gave a presentation on matter.

What did you think of the Observation Lab... here's what the class said
-fun :)
- interesting to mix chemicals
- involved a lot of independent work, unlike last year
- had to work quickly in the lab due to limited amount of time
- stations were crowded
- took longer time to clean up (Mrs. Friedmann said leave about 5 min at the end of labs to clean up)

***Mrs. Friedmann also said that you do not have to bring your spiral lab notebook to record your "final" data in class. You may do that work at home and record your rough observations in your notebook in class.


Variables and Experimental Design

Quick Review: 
-Independent variable = what "I" (the experimenter changes).
-Dependent Variable = what is observed and measured. It is the result that is caused by changes in the independent variable. Dependent variable must be measurable or qualitative data.
                               - Qualitative data= no numbers
                               - Quantitative data= numbers

Controlled Variable(s)= everything else I try to keep the same from trial to trial.

Today:
Utilizing the information listed above we completed a worksheet, in which we had to identify the 3 variables in a scenario. After completing the worksheet we took a small quiz.

How Do Chemist Classify Matter?
In class, Mrs. Friedmann gave a presentation on how matter is classified. The notes accompanying the presentation can be found on Moodle. Here are the additional notes Mrs. Friedmann wrote on the board during the presentation.

Chemistry= the study of MATTER

-Matter can be divided into 2 categories: Pure Substances and Mixtures
- Pure Substances can be further divided into Elements and Compound
 PURE SUBSTANCES

            Elements                                                                     
- About 110 of these                                                
- Can't be broken down into simpler form              
- All atoms of one element are same (in certain          
key ways)

        Compound
-Many types of these
- Different elements are chemically combined by
bonds( can be considered as "glue" for now)


- Mixtures can be further divided into Homogeneous and Heterogeneous
MIXTURES (physically combined, not combined by bonds)

          Homogeneous                                                                                                                        
- All parts of the mixture have the same parts                  
EX: Where ever you take a sample from a sugar mixed      
coffee it will have same amount of sugar and coffee.          

          Heterogeneous
- One part of the mixture may have different amount of
substance than another part.
 EX: If you take a sample of sand from one part of the beach
it will be different from the other part of the beach.

Homework: 
To answer this question...
 -Suppose I make a taco salad for lunch. Can the salad be best described as Compound, Homogeneous mixture, or Heterogeneous mixture. Why?
- WebAssign safety quiz was due by 11:59 today

Beach sand

Coffee

Small text: That isn't dark matter sir --- you forgot to take off the lens cap

The next scribe post author is Janet Nwosisi

Observation Lab

8/26/13 Scribe Post Author:Suvd Davaadorj

Today, Ms.Friedmann went over the basics we should know for a lab then we did the observation lab.

Lab

Variables

• Independent:  What I change ( as the experimenter )
• Dependent: Data (What I observe and measure)
• Qualitative-no numbers
• Quantitative-numbers
• Control: Everything else that I try to keep the same from trial to trial 

How to Use Your Student Lab Notebook (The Carbonless)

• Use the flap with the periodic table to prevent bleeding through the pages because it will bleed multiple pages. First, check the number on the top right hand corner of the page you are using. Make sure that the blue and yellow sheet behind it have the same number then put the flap under these two pages.

Labs MUST Have:

• Title
• Purpose
• Data
• Calculations-Not in this lab!
• Post- Lab Question
• Conclusion- Not in this lab! ( Lesson on this later!)

Format on Lab Notebook: 

• Fill out the top of the page (this includes the title, date, name, lab partner)
• Write Purpose
• Write Data and draw a box filling up the top half the page and label it A then draw another box filling up the bottom half of the page and label it B

Turning In Your Lab:

• Use complete sentences
• No need to rewrite the questions
• Keep the blue paper and tear out the yellow paper to turn in  

Remember: When you turn in your lab, your data and everything should be very NEAT!

Lab Results

Part A:

Substance                                                                                                

1. Calcium chloride                                                                  

2. Sodium bicarbonate                                                             

3. Phenol red                                                                                

4. All three combined                                                                    

Observations    

1. white, clumpy, looks like hail
2. white, looks like baking soda
3. orangish red, liquid
4. yellow, fizzy, warm

Part B:

Experiments

1. CaCl2 + NaHCO3 = No reaction
2. CaCl2+H20= Hot
3. NaHCO3+ Phenol Red= Purple/Pink
4. CaCl2+ Phenol Red+ Yellow and Warm
5. NaHCO3+H2O= Fizzy
6. CaCl2+ NaHCO3+H2O= Fizzy and Cold

--------------------------------------------------------------------------------------------

Calcium chloride :

Sodium bicarbonate:

Phenol red:



The next scribe post author is Ambreen A.

Zombie Bubbles & Lab Safety Video

8/22/13 Scribe Post Author:Serene P

Today, we learned about Observations versus Inferences. Also, we watched a video about lab safety.

Zombie Bubbles

Mrs. Friedmann used her "Zombie Bubble" tank to present her demonstration. First, she sprinkled baking soda covering the bottom of the tank. Then, she spilled some vinegar in which caused the substance within to become fizzy.

Observations                                             

1*Baking soda and vinegar = Fizz!

2*Fizz dies down approximately after one minute. 

3*The substance smells like vinegar.

4*There was about a quarter inch or 1/2 of a centimeter of liquid at the bottom of the tank, but the rest of the tank was clear and colorless.

5*Bubbles float in the tank.

Inferences

*Based on observation four, there is nothing in the tank except for the liquid at the bottom. 

-However, this assumption was tested. Mrs. Friedmann poured more vinegar and baking soda into the bubble tank causing the fizz to greatly increase. Then, she used a bottle of bubbles and started blowing bubbles into the tank. When the bubbles entered the tank, they were actually floating around in mid-air of the container and travelling in an upward-downward trend. Therefore, this result proved that the previous inference made was incorrect. 

           The revised inference of the previous inference of observation five:

*There is something in the tank, but it is invisible. 

Note:

        The reaction of the fizz was an indication that carbon dioxide was produced. However, it was not visible to the sight. The bubbles that were blown into the tank showed the presence of the carbon dioxide. 

         Soon, Mrs. Friedmann used a large spoon and gathered carbon dioxide from the tank. She then put and exposed the collected carbon dioxide into the lit candle of fire. This caused the fire to flicker and eventually be put out once contact was made. This indicated that carbon dioxide was present in the tank. The collected carbon dioxide from the tank extinguished the lit candle demonstrating that this gas was present in the tank. 

Lab Safety Video

*Being safe in the lab should be a top priority for a chemistry student working in the lab. It is important to follow all rules and safety precautions in order to have a good learning experience. 

Safety Tips:

*Tie long hair back

*Wear safety goggles at all times 

*Handle chemicals safely

-Make sure to not have chemicals contact the skin or eyes. 

-Use small containers to control easily

*Only mix chemicals when your instructor approves

*Mixing chemicals correctly can prevent accidents

-Add sulfuric acid to water. If done oppositely will result in unsafe boiling of the substance.

*Read and reread instructions 2 to 3 times.

*Make sure you understand directions and read them completely. Ask questions if you have any doubts. 

*Follow the instructions exactly as mentioned.

*Use clean glassware

*Accidents occur. Inform your instructor immediately.

-Allow your instructor to clean up any spills.

*Keep chemicals and lab materials away from your face and body.

*Keep a work tray by you since spills occur often.

*Hold bottles with hands over label

*Hold coin top stopper between fingers

*Replace stoppers immediately

*Use a pipette. Do not use your mouth in any way to collect and transfer chemicals.(As Marie Curie)

*Do not set bottles in a position in which they could easily spill.

*Do not touch or smell substances directly. Only light whiffs might be permitted. 

*Volatile chemicals should be handled under a fume hood.

*Never pour excess chemicals back into their original bottles. It is better to waste them. Do not contaminate bottles.

*After measuring the reagent, dispose of it.

*When a spill occurs, use a good absorbent to clean the substances. Kitty litter works well but may not be used much in our class.

*Waste residue should properly be disposed.

-broken glassware should be placed in the proper disposal

*Clean up glassware thoroughly when finished.

*Clean chemicals off hands.

*Don't throw anything into the sink unless instructed by teacher.

*Clean up lab station thoroughly. Clean yourself up. 

            https://www.google.com/search?gs_rn=25&gs_ri=psy-ab&tok=PVMu_gGgikPuYj31XQagjA&cp=7&gs_id=1b&xhr=t&q=lab+safety&bav=on.2,or.r_qf.&bvm=bv.51156542,d.aWc&biw=1366&bih=667&um=1&ie=UTF-8&hl=en&tbm=isch&source=og&sa=N&tab=wi&ei=V40WUvidBeG9yAGAzIHYAQ#imgdii=_ -image citation

The next scribe post author is Lauren B.