Due today: Avogadro's Number
Homework: Moles 1 worksheet (there is a backside!) and Avogadro's Number lab

Hello! We started off class with Lab questions. Remember, on the calculation part of the lab, there are useful facts and figures and irrelevant tid bits down at the bottom of the paper. The purpose of this lab is to give a better understanding of the magnitude of Avogadro's number. If you didn't understand number 1, here is the equation to solve it: 

1 mole of rice × 6.02×10^23 × 56 sec/100 Rice × 60 sec/1 min × 60 min/ 1 hr × 24hr/ 1 day × 365 days/ 1yr. 

Also, Jane, Madison, and Jake measured 1 mole of iron, copper and aluminum. They came out to be pretty close to the atomic mass from the periodic table. You can always simplify Hydrogen to 1 or Nitrogen to 14, but elements like Chlorine can be simplified to 35.5. This is also known as the Molar Mass. It's equal to the numerical value of the average atomic mass, and the units should be grams per mole. Avogadro's number is usually used to measure BIG numbers and put it into scientific notation. (Such as the number of atoms, or molecules.) Mr. Lieberman showed us red liquid in a graduated cylinder. It looked like a small amount of liquid, but there is a mol of water molecules in it.   

Example)
 
1 Mole of CaCl ^2 = 111.1 g/mol 

1 mole Ca × 40.1 g/mol
+ 2moles Cl × 35.5 g/mol = 71 g/mol 
                                        = 111.1 g/mol CaCl ^2 

Here is an example of Avogadro's number from the Homework from Wednesday:

A sample of pure acetic acid, CH^3COOH, contains 1.4×10^23 carbon atoms. How many moles of acetic acid are in the sample?

1.4×10^23 × 1 molecule/2 atoms × 1 mole/ 6.02×10^23 = .116 moles.

ALSO, if you still do not understand Avogadro's number, the mole, and conversions, click here and watch it:http://www.youtube.com/watch?feature=player_embedded&v=AsqEkF7hcII#!


Next scribe is: Benya C

Moles and Avogadro's Number

Amedeo Avogadro

Due Today:  Naming Workshop worksheet
Quiz on Naming Ionic and Covalent Bond and Acids

Due Thursday:  Avogadro's Number worksheet
Due Friday: Avogadro's Number Lab

          After the daily routine of checking the homework Mr. Lieberman started to explain Avogadro's number and the mole using a packet he had handed out. We first learned about an Italian scientist, named Amedeo Avogadro, who conducted a series of experiments, to discover a specific number of atoms, N sub A, that is constant regardless of the element if and only if the mass of the sample of the element in grams is numerically equal to the atomic mass of the element. Knowing Avogadro's number makes it possible to calculate the mass of an individual atom.
Avogadro's number is as follows:

6.022 X 10^23 

There are:

6.022 X 10^23  H atoms in 1.008 g H

6.022 X 10^23 He atoms in 4.003 g He

6.022 X 10^23 S atoms in 32.07 g S

The name given to Avogadro's number is 6.022 X 10^23. A mole represents an enormous quantity and is used as a conversion factor: 

 Here's a sample problem:

How many moles are in 7.8 X 10^24 atoms of carbon?

(7.8 X 10^24) X (1 mole/6.022 X 10^23 atoms) = 12.9525 moles

At the end of class we did an experiment regarding Avogadro's number to further our comprehension of the matter. In this experiment we collected data, based on a rice grain, to use as conversion factors to solve problems using dimensional analysis.

The next scribe will be Josh M.

Acids and Quiz Review

Due Today: Naming Practice worksheet
Today's Homework: "Naming Workshop" worksheet and study!

As usual, today we started off class by checking in the homework.*Please remember to have Mr. Lieberman stamp both sides of the worksheets for upcoming homework checks*













Next Mr. Lieberman talked about Acids and their properties. These were from the notes from the beginning of the unit.  If you do not have the notes they are available here on moodle.  If you do not feel like printing out all the notes, today we only discussed the last three slides. We discussed the properties of Acids and how to name acids.  Acids are found when certain molecules are put in water.  They ionize to form H+ ions.


If the second ion, the anion, does not contain oxygen, then you change the ending of the acid to "ic" and add the prefix hydro.  However, if the anion DOES contain oxygen, "ate" changes to "ic" and "ite" becomes "ous".  Mr. Lieberman came up with a silly/convenient way to remember this: ATE-IC, ITE-OUS.

  
The last section of the notes were about the Oxoacids. Mr. Lieberman said there was no pattern to memorizing these so just study them!

Next we reviewed for the quiz we had today.  We used whiteboards to write formulas and equations for certain compounds. In the last ten minutes of class, we took to the quiz.  If you did not take the quiz today, please take it as soon as you can with Mr. Lieberman or in the test center.


REMEMBER: Study the ion chart for the quiz tomorrow because you will not be able to use it.

The next scribe will be Tommy R.

Ionic and Covalent Bonds

Ionic and Covalent Bonds


Homework for Monday: Naming Practice worksheet
                                       Quiz Monday- Covalent Naming

On Thursday and Friday, we began to study two types of bonds between atoms, ionic and covalent bonds.


Ionic bonds
      On Thursday we began learning about ionic bonds. An ionic bond is a bond formed between one positive and one negative atom. We began with a worksheet that helped us better understand what an ionic bond was. For example, we had to list any similarities that we noticed between several examples. These similarities included that the first element in an ionic bond was a metal, and that the second element was a non-metal that ended with the suffix -ide. Below is an example of how an ionic bond is formed.
Ionic bond:

On Friday, we started class with a short quiz on ionic bonds. After the quiz, we started a worksheet, similar to the one about ionic bonds, that introduced us to covalent bonds.

Covalent bonds

     On Friday after the quiz, we began to learn about covalent bonds. As mentioned above, we started a worksheet that introduced us to covalent bonds. A covalent bond is a bond formed between two atoms that share electrons. We identified patterns that we noticed between examples given on the worksheet. Some similarities were that the second element ended with -ide, both elements used Greek prefixes, and the first element is a non-metal. 

Covalent bond:

We also began learning how to name and identify the two types of bonds. Some examples for naming ionic bonds are:

Copper (I) Chloride ---> Cu2Cl

and Iron (III) oxide   ---> Fe2O3

Covalent bonds use Greek prefixes for naming compounds. Some examples for naming covalent bonds are:

NO2 ---> Nitrogen dioxide

CO   ---> Carbon monoxide    If you noticed, in this example a prefix for carbon was not added, because as a rule prefixes              .                                                   are only added to the first atom in a covalent bond if there is more than one. For example:

P2O5 is diphosphorus pentoxide

The quiz monday will cover covalent bonds and covalent naming, as explained above.

The next scribe will be Johnny O. 

Meet the Elements

Meet the Elements

Due Today: Nothing
Homework: Metal, non-metal, metalloid lab, Atomic structure worksheet, Isotope Chemthink.

Today in class we met the elements! First we watched a nifty music video: "Meet the elements" to introduce us to the topic. Next we were introduced to the elements in our Metal/Non-metal/Metalloid lab. A: Aluminum B: Carbon C: Silicon D: Tin E: Sulfur F: Magnesium G: Zinc H: Iron. We identified  the elements as metals or non-metals by their appearance and luster, as well as malleability. Then we moved on tho the elements arranged in the periodic table, as introduced by Dmitri Mendeleev.

 We learned about the major groups in the periodic table. Alkali Metals (the group on the far left, not including Hydrogen), Alkaline Earth Metals (second to the left), Transition Metals (the middle groups that aren't in periods 1, 2, or 3), The Halogen Family (second to the right), the Noble Gases (group farthest to the right), and the Rare Earth Elements (The rows underneath the rest of the table). Next we discussed the three things that make up an atom, Protons (which have a positive charge and are located in the nucleus), Neutrons (which have a neutral charge and are located in the nucleus), and electrons (which have a negative charge and circle the nucleus). 

Finally we discussed Isotopes, which are atoms that have more or less neutrons than they normally do. examples of these include Deuterium, a hydrogen atom with a neutron, and Tritium, a hydrogen atom with two neutrons. For reference, here is the "Meet the Elements" video, which provides a good overview of what we learned in class. 

The next scribe will be Brian F.

Metal, Non-Metal and Metalloid Lab

Due Today: Nothing! The Unit 1 Exam was on Friday and there was no homework assigned over the long weekend.

Homework: Lab due tomorrow, 2.3- The Periodic Table- reading and WebAssign (Due 10/5).

Today in class, we got our exams back from Friday. We went over any questions that came up while taking the exam. Grades are up on Homelogic. If you have any questions about the exam or you would like to see your test, please schedule a time with Mr. Lieberman.

After we went over the exam, we began the Metal, Non-Metal, and Metalloid Lab. The goal of this lab is to identify several elements based on their chemical and physical properties. On the periodic table, all elements can be classified as either a metal, non-metal, or a metalloid. In this lab, we put eight substances through some tests to determine their malleability, conductivity, and abilities to react with HCl and CuCl2.

Metals: Elements that have luster, are malleable, and conduct electricity. Many react with acids and CuCl2 solution.

Non-Metals: Dull in appearance, brittle, and do not conduct electricity. Usually don't react with acids and CuCl2 solution.

Metalloids: Have at least two properties of both.

        

   

The appearance was recorded into a data table without any tests being conducted, as well as the luster (if it's shiny or not). But then, to test malleability, we whacked the substance with a hammer and determined if it the metal flattened (was malleable) or was smashed into pieces (was brittle):

Next, conductivity was tested. To do this, a piece of a substance was put across two pieces of wire sticking out of a battery contraption. If the substance conducted electricity, then the lightbulb on the end lit up:

Finally, the substances were tested for how they react with HCl and CuCl2. If the substance reacted with HCl, it usually rusted in the tray. A common reaction with CuCl2 would be bubbling with, potentially, a color change:

Here's a picture of the reaction between substance F and CuCl2:

Hope this helps!
The next scribe will be COLIN B.

Separating Mixtures Lab 9/12/12

Separating Mixtures Lab

Due today: Beverage Density Lab, written procedure for Separating Mixtures Lab

Homework: Separating Mixtures Lab due friday, also test friday, and optional review sheet on moodle. 

Today at the beginning of class we got our 1.2 quizzes back. We did not go over any questions form the quiz, if you wish to do so you can meet with Mr. Lieberman outside of class. 

Next, we started working on the Separating Mixtures Lab. The goal of the lab is to seperate a mizture into it's components and determine the mass % of each component of the mixture. The mixture we used was made up of iron, salt, and sand. In your research you should have studied the properties of each component. 

iron: magnetic solid, insoluble in water

salt: non-magnetic solid, soluble in water

sand: non-magnetic solid, insoluble in water

From these properties, you should have been able to create a procedure determining the mass % of each component. This is the procedure my lab partner and I cam up with:

picture 1

picture 2

1. Using a scale, find the mass of the iron, sand, and salt mixture. The result for my mixture was 2.07 grams.
2. Obtain a magnet in a plastic bag and wrap a paper towel around the corner of the bag with the magnet in it. Slowly swipe the paper-towel covered magnet in circular motions over the mixture staying about 1-2cm above the mixture (picture 1).
3. Carefully remove the paper towel with iron on it from the magnet. Find the mass of the  iron by massing a small empty weigh boat on the scale, then pour the iron onto the weigh boat and mass. To find the mass of the iron subtract the mass of the weigh boat from the mass of the weigh boat with the iron in it. For mine, the mass of the iron was .46 grams.
4. Warm 25mL of water in a beaker on a hot plate.
5. Pour in sand and salt mixture and stir until salt is dissolved. 
6. Prepare filter paper by folding it into quarters and placing in a funnel. Place the funnel on a clay triangle on top of the beaker to suspend and hold the funnel in place (picture 2). 
7. Pour dissolved salt and sand mixture into filter. Collect salt water and pour sand back into beaker.
8. Place beaker with sand onto a hot plate and heat on the lowest setting. Heat until all residual water is evaporated (picture 3). 



picture 3

9. Mass an empty, small weigh boat. Pour sand onto weigh boat and mass. To find the mass of the salt subtract the mass of the empty weigh boat from the mass of the weigh boat with the sand (1.2-.52). The mass of the sand in my experiment was .68 grams.

That is it for the procedures done in class, the rest is all calculations. To find the mass of the salt, you need to add together the mass of the iron and sand (.46+.68=1.16.) then subtract that from the mass of the iron, salt, and sand mixture (2.07-1.16=.91 grams). 

That's all for today. This lab is due friday and don't forget we also have a test friday!!

NEXT SCRIBE: KATIE 

Beverage Density Lab

  

Beverage Density Lab

  Hey everyone, today in class we did the Beverage Density Lab!  The goal for this lab was to determine the % of sugar content in several different samples of beverages.  For this lab you must know the formula for density, density = mass divided by volume.Before extracting samples we had to find the mass on the balance of the beaker each time we used it so our measurements were precise and accurate. Then we had to use the pipets to extract exactly 5 mL of 5 different solutions mixed with a certain percent of sugar (0%, 5%, 10%, 15%, and 20%).  Once in the beaker, we had to find the mass of the solution.  Now to find the mass of the true solution you have to subtract the mass of the beaker from the mass of the solution in the beaker.  For example, I got 56.81 g for the mass of the 5% sugar solution and 50.80 g for the beaker.  To find the solution's mass I had to do 56.81 - 50.80 = 6.01 (mass of only the solution/liquid in the beaker.)

  After recording all the data you had to make a graph with

density on the y-axis and % of sugar on the x-axis.  This graph should be discrete, a set of points, because all your results all data points not an infinite amount of data that a line graph would support.

  Part B was to choose two of the three other beverages to find the mass, volume, density, and % sugar to.  I chose grape juice and apple juice with my partner while we didn't do Pepsi.  You also had to mass the beakers every time for this portion of the lab.  In the end you have to answer the questions for claim, evidence, and reasoning in your conclusion.  Do it in your carbon-less lab notebook and turn it into Mr. Lieberman tomorrow! Good luck!

THE NEXT SCRIBE WILL BE DANA G.

Accuracy, Precision and Metrics

Accuracy Vs. Precision 

Today in class Mr. Lieberman began teaching us the difference between being accurate and being precise during labs. We started with a game involving three volunteers including Dana, Georgia, and Katie. They were asked to use a plastic gun and shoot rubber bullets on a bullseye. After doing this demonstration, we learned that being accurate (like Dana was) is dependent upon how close you get to your ultimate goal or the answer, in this case, the bullseye. We also learned that being precise is dependent upon how many times you produce the same action, in this case, how many times you hit the  board in the same place.

Metrics!

Mr Lieberman also taught us all about the metric system. He stressed how it was necessary to include units in all of our labs and the units we will use include meters, liters and grams. And the most common prefixes we will use include kilo, centi and milli. 

Kilo= 10^6

Centi= 10^-2

Milli= 10^-3

CAN THESE SITUATIONS BE REALISTIC?

       Can this pencil be 200 grams?                           Can this girl drink 25 milliliters of water?                 

Yes, this situation is realistic.

                                                                                     

No, this pencil is probably about 10 grams.

THE NEXT SCRIBE WILL BE BILLY K.

Physical vs. Chemical Change

PHYSICAL VS. CHEMICAL CHANGE 

Today in class Mr. Lieberman preformed an experiment demonstrating a change in magnesium. There are two types of possible changes that something can preform, physical and chemical. A physical change is when there is a  difference but the substance its self didn't change, it describes the nature of the substance you are looking at. An example would be a color change. Physical changes can be caused by melting point etc. In contrast a chemical change is when the substance is transformed into something else entirely. A chemical changes means that the atoms have been rearranged. The video below is the experiment that was preformed in class. This is an example of a chemical change,  magnesium becomes magnesium oxide, which makes it a completely different substance.

Magnesium-> Magnesium oxide 

This picture shows the results of the experiment we did in class, the solid straight metal piece is what we began with,the plain magnesium, after putting it through the flame the magnesium oxide was the result. Although this may appear a physical change because it looks different, it is a chemical change. This is because it is no longer magnesium but now magnesium oxide so it is a completely different substance. 







The next scribe will be.....
SHANA M.