Density and Excel

We started off class by being told by Mr. Lieberman that we will be going to the math lab very quickly so he can show us how to make our graphs for post lab question one for the density of pennies lab. You are supposed to go on microsoft excel and then fill in the the A column with the calculated volume of the pennies. We just did the pre 1982 pennies for now. Then in the B column you type in the mass of the pennies. After we put in the numbers we made a graph of the numbers and printed it out and we have to staple it or glue it in our lab books. To make the graphs we first highlighted the data. Then you click on the insert tab and click charts and choose a type of graph. Next to make the x axis say volume you click on the chart itself then click the layout tab and choose labels. Then click axis titles and it will say x axis and y axis and click on those to be able to make a label for the axis. We left the math lab and came back to the classroom and started talking about density.

Mr. Lieberman showed us an experiment about density and in the experiment he set two beakers up with clear liquids in each and they had approximately the same volume, but Mr. Lieberman never said they were both the same liquid. Next he dropped an ice cube in each beaker and immediately one ice cube sunk and the other floated. The reason why it sunk was because the ice cube had a greater density than the liquid. The other ice cube floated because it had a smaller density than the liquid.

Here are some things you should know about density: it measures how much mass there is a an amount of space which is volume. The way to calculate density is mass divided by volume. Also be sure you know how to calculate volume if you were given mass and density and how to calculate mass if you were given volume and density. There is a special triangle to help those of you who are 'algebraically challenged' that will help you remember these formulas. Just another regular day in sixth period chem.

And the next scribe is....Becky N.

More figs, more fun! Sig Figs..

Well, maybe it's not exactly fun, but today class was all about the numbers in chemistry. More specifically, Sig Figs, or Significant Figures.

To start things off, we first went over the Metrics worksheet we had for homework. (Some new metric measurements that were not in the notes was hectogram (hg) which is equal to 100 grams, and cm^3 = 1 ml) One of the things we checked checked for was estimating past the last readable digit, meaning if the last digit of a measurements is in tens, then you would estimate to ones to leave room for error.

On a bit of a side note, the last problem on the worksheet showed an illustration of a buret, which appears to be measuring upside-down, but is in fact correctly labeled. Mr. Lieberman told the class that we would be using this instrument a lot in second semester. (I added the picture simply because of the lack of color....and for a visual of course..)

For the rest of class, we got another worksheet (for homework) and went over notes for sig figs and scientific notation, which is, as most of us already know, something like 590000 to 5.9 x 10^5 to show the number of significant numbers.
However there are also some rules to sig figs that play into measurements and the scientific notation. For precision's sake, these rules are:
-nonzero integers count as sigfigs
-leading zeros are never significant (0.000757 has 3 sig figs)
-captive zeros always count as significant figures (such as in 16.07, there are 4 sig figs)
-trailing zeros are only significant if the number contains a decimal point (9.300 has 4 sig figs. If the number were 500, there is only one sig fig, unless it was written as 500.0.)

For mathematical operations, there are different rules for adding/subtracting and multiplying/dividing:
Adding/subtracting : the # of sig figs in the result equals the number of decimal places in the least precise measurement.
EX: 6.8 + 11.938 = 18.734, which turns into 18.7 (for 3 sig figs)

Multiplying/dividing : the # of sig figs in the result equals the number in the least precise measurement used in the calculation.
EX: 6.38 x 2.0 = 12.76, which becomes 13 (2 sig figs)

(All of these notes can be found on the powerpoint)

And with a schedule that was shifted around, we ended class in 40.0 minutes.
As a reminder, we have a quiz on the measurements and sig figs we went over tomorrow. The quiz Mr. Lieberman assured would not be as easy as our first quiz.. Good luck to us all..
and the chosen one to be scribe tomorrow will be... Zoe S.

What's Wrong with a Little Change?

To start Chemistry class today, we discussed the Mixtures Lab (due tomorrow), and Mr. Lieberman asked if there were any questions. Question number 6 seemed to be confusing. Mr. Lieberman explained then to ignore it, or write the mass percent of each substance in the mixture.

Next, after turning in the Paper Clip worksheet from last week, we took notes on a powerpoint about chemical and physical propertieds and changes. Remember:
a Physical Propety is one that can be observed without a new substance being formed (ex. boiling point, melting point, texture, etc.).
a Chemical Property is a property that tells us how a substance would react in a given circumstance (ex. at what temperature does cinnabar split into mercury and oxygen?)
a Physical Change is a change that can be observed without the formation of a new substance, including change of phase. (ex. water freezing, boiling, a rock being smashed).
a Chemical Change is a change of a substance into a brand new substance. (ex. a bomb exploding, wood burning, banana ripening).

Finally, went over the prelab for "What Chemical Reactions?", which discusses properties and changes, and also determines that "corrosive," a property of HydroChloric acid, means damaging to skin and clothes, and then started the lab. Most of the groups did not get far because of limited time, but we did get to see some Chemical reactions. We will finish it tomorrow.

Sorry no pictures... I didn't get any good ones. The next scribe will be: Ben T

Fe! Fi! Fo! Fum! (And NaCl and SiO2!)

So today, the class began a new lab. In this lab, we had to observe three different mixtures; sand, salt, and iron. Some things we observed were if they were soluble in water, if they were magnetic or not, and other various physical properties. While observing, we made sure to all wear our goggles, because even though things like salt and sand may seem harmless, they still could accidentally get in our eyes and damage them! So, with all the correct safety gear in place, we observed closely, as our brains got to work.

Part A had us mix the sand, salt and iron in about 10mL of water. After doing so, we observed that the salt had dissolved into the water, but the sand and iron filings had not. So, we then used a filter in a funnel to separate the salt water from the sand and filings.

After doing so, we placed the wet filter paper on a hot plate with the wet sand and iron, which was supposed to dry out any excess water left on the sand. That was about the farthest anyone got before it was time to clean up and the bell rang, signaling the end of the class.

When we were dismissed from class, our homework for tonight was to come up with a group procedure for Part B of the lab. The procedure is a way to separate salt, sand, and iron filings. When we come into class tomorrow, we will receive a small tube that has an uneven amount (heterogeneous!) of those three things. I won't talk too much about tomorrow though, because I don't want to steal the next scribe's material.

Which leads me to the next topic that I know we've all been waiting for; tomorrow's scribe!!! Yay! The scribe for tomorrow (technically the weekend) will be none other than Joshua D.!

That'll be all the news from today's Chemistry class. Thanks for reading. You stay classy, Period 6. I'm Aaron G.

All Powerful Atoms

Representing Matter

View more presentations from gbsliebs2002.

Today in Mr. Lieberman class we started off the day with a quick congrats to Emilio on his post, and also talked about how to upload photos onto the blog. During the beginning of class a few students mentioned they forgot to do the ChemThink assignment Particulate Nature of Matter assigned the night before. So, Mr. Lieberman said if you could finish it before it was graded it would count as a full grade, so hurry to do it before he checks. Lastly, Mr. Lieberman collected all of the classes "Observation Labs". If you missed today’s class expect to turn it into to him tomorrow. Mr. Lieberman also notified us that our Web assign homework and safety tests were graded, and you can log on to see your grade. Next, we proceeded to take notes on our first unit. These notes included the fundamental unit of Chemistry the Atom. Also, in the notes we went over elements, molecules, and compounds for example Splenda or, Sweet and

Low. First of all an element is the simplest of pure substacnes. Which, brings us to what a pure substance is. A pure substance is a substance made out of all the same elements or compounds or mixtures. For example gold. Also, a pure substance cannot be seperated into smaller substances. We also learned about compunds. Compounds are a molecule that has two different kinds of atoms in it like oxygen and hydrogen. Next, we learned about mixtures which, are compnents that retain their own identity, and can be seperated physcially. Mr. Lieberman taught us an acronim to learn the 7 different diatomic elements (diatomic means two atoms,) HONClBrIF. This stands for Hydrogen, Oxygen, Nitrogen, Chlorine, Bromine, Iodine, and Flourine.

We also learned about pure substances, classification, mixtures, Homogenous mixtures, and Heterogeneous mixtures. During the notes Mr. Lieberman told us a few fun facts for instance we learned that lead's Latin name is plumbum. So, plumbers got their name when they worked in Rome on the aqueducts, which used lead. The class notes are represented above this blog post.

After this we began our Paper Clip Activity. In this activity we had to use colored,

small, and jumbo paperclips to compose atoms. We were given a partner to complete all of the atom molecule combination problems, and then Mr. Lieberman had checked off our your creations. There are five sample questions to complete for homework tonight.

Finally, Mr. Lieberman assigned us a Pre-Lab for tomorrow’s lab "Separating Mixtures". Make sure you get that done for tonight’s homework. The next scribe shall be Aaron G

Finishing up the Lab

The class today was in a fairly good mood when Mr. Lieberman started us off by congratulating Kathryn on her wonderful scribe post and notified me about mine. We continued to talk about the blog and functions such as the photo issue that is now resolved, and immediately after, went to finish the "Observation Lab."

We were told to complete part B of the experiment by creating our own experiments to discover what reagents, when mixed together, caused certain reactions. Of course, we were told to record all observations in our handy "Scientific Lab Notebooks." My lab group, and most other lab groups, executed a total of five experiments and for some, more than that. It was fairly easy work, and the results were astonishing. For example, when the four reagents, sodium bicarbonate, calsium chloride, water, and phenol red, were combined in the plastic bag, we came up with an opaque, yellow, fizzy liquid (shown in the picture). Very interesting stuff. Aside from the two glass beakers shattering on the floor, all went well.

The class, at their own desks, took up netbooks and registered themselves to ChemThink, in order to complete the assignment Mr. Lieberman assigned.

Homework: ChemThink and worksheet "Particulate Nature of Matter," and the eight Post Lab Questions.

Pretty easy day, it was very relaxed and enjoyable. Who knew Mr. Lieberman was into Weezer?

The next Student Scribe is Brandon L.

Observing Monday

The very beginning of today's class began with at least 5 students informing Mr. Lieberman that the bookstore was once again out of Chemistry notebooks. Then, we spent the first ten minutes reviewing how to use this Blogger website, mostly for my benefit. Mr. Lieberman showed us exactly how to create a post and how to accept his e-mail invitation to become an author on the blog. He also clarified that if you are assigned to scribe on a Friday night, you must have it completed by Sunday evening and showed us the link to his YouTube channel, where demos would be available on video.

Next, we went over our pre-lab questions for the Observation Lab that we had been assigned over the weekend. We were told again that we MUST where our goggles in the lab at all time, because as John put it, substances might contaminate our "ocular cavity". Oh, and bias is not a part of the scientific method. Science is based on straight facts, not on your own personal opinion.

We then moved on to the art of creating a data table. Mr. Lieberman drew an example for us, and then showed us the lab set up in the back of the classroom.

We broke up into our lab groups, donning our fashionable green goggles from the GBS bookstore. Following the lab procedure, we mixed calcium chloride (snow salt), sodium bicarbonate (baking soda), and phenol red in a plastic baggies. The reaction took place and we discovered that the phenol red had actually turned red (instead of the orange color it was originally) and that most of the sodium bicarbonate and calcium chloride had dissolved. We recorded our observations in the data table we had created earlier.

Next, we began to design our own experiments to figure out why this reaction took place, mixing the difference substances (plus water) together in their own separate baggies to see which individual reactions stood out.

Unfortunately, we did not get much time to finish the second part of our lab. The bell rang, and all the kids in six period Honors Chemistry rushed out the door, goggle marks lining their eyes.

In good news, the 2010 JV Girls' Volleyball Team beat York in the first game of the season! Woohoo!!

See you tomorrow in class! The Observation Lab is due Wednesday. Go Titans!

The next student scribe is...Emilio!

P.S. The pictures aren't loading on my computer, so I'm sorry this is not very exciting. I'll try on a computer at school!

Safety Part 2

Today's class we continued our discussion on safety and started to prepare for our first lab. We watched another clip from the ACS safety video. This shorter clip had to do with good lab techniques. There are several points that I think are worth highlighting.

1. The video made a point of telling us that it is always smartest to pour liquids from large stock bottles into smaller containers that are easier to manage in the lab.

Ahh...the memories

2. The point of mixing acids is an important one but not done very often in our class. Acids should always be poured into water, not the other way around. "Do what you outta pour the acid into the watta" I know lame but I learned that in high school myself.

3. The video also commented on how we always pour out of stock bottles but never back in. If you have too much of a chemical dispose of it properly but do not put it back into the stock bottle.

4. Remember never mouth pipet!!

After that we briefly discussed how to do the pre-lab for Monday's Observation Lab. We will discuss the data tables on Monday also. Lastly we briefly talked about the unit objectives that were handed out. These are just the main topics for the current unit. They will be handed out at the beginning of each unit. Remember that if you missed a handout for an absence please go to our moodle site to download them. The last thing we did was took our safety assessment on WebAssign.

V-I-C-T-O-R-Y!!!

Have a great weekend and go Titans!!
Oh yeah our first student scribe is...Kathryn J