Tuesday, November 23, 2010

Mole Conversions for the Gifted (Self-Made Video Surprise Included!)

We have returned with a smashing video of our 3 favorite characters!

Harriet, played by Hanae Aso.
Savannah, played by Melissa Chan.
JiaLiu, played by Jessica Tsui.

Please enjoy this fun and entertaining video!

Sunday, November 21, 2010

The All Powerful MOLE

Hello Readers,
Today we will be focusing on this little strange creature right here:



Don't you think this creature is fascinating????
Why yes is, you reply, but I don't think this is what we're supposed to be focusing on. AND YOU ARE COMPLETELY RIGHT.

Actually, what we learned in class was mole conversions. In order to completely totally utterly understand conversions, you must know the mole map which I will oh so kindly show you:



Converting PARTICLES <-> MOLES
Remember, there are 6.022x10²³ particles in one mole
6.022x10²³particles
1 mole

So lets have an example now shall we?

Say there are 6 x 10^24 particles of carbon and somebody out there really wants you to convert that into moles. What will you do? I'll tell you:

6 x 10^24 particles x 1 mole/ 6.022 x 10²³ = 9.96 moles of carbon

Converting MOLES <-> PARTICLES/MOLECULES/FORMULA UNITS/ATOMS
Lets have an example:

Say that you have 4 moles of water (H20)and you NEEDED to find how many molecules there were within the water you had. Here is how you do it:

4 moles x 6.022 x 10²³ molecules/ 1 mole = 2.4 x 10^24 molecules of H20


LAST BUT NOT LEAST. Hold on to your horses guys, we're almost done.

Converting MOLES <-> GRAMS
Last example of the blog:

For example, you are given 1.5 moles of carbon and you needed to change that into grams. This is what you must do to gain ultimate world domination:

1.5 moles x 12.0 g/ 1 mole = 18.0g of Carbon

And there you have it folks.

Friday, November 12, 2010

Lorenzo Romano Amedeo Carlo Bernadette Avogadro di Quaregna e Cerreto



Lorenzo Romano Amedeo Carlo Bernadette Avogadro di Quaregna e Cerreto

No jokes!


Hello everyone, this is Melissa from the Smarticle Particles. I hope you enjoyed the above photo of that dashing and handsome man!

Just for the ease of typing, we are going to call him Avogadro for the duration of this entry. Anyways, this was his hypothesis...

- Equal volumes of different gases will have the same number of particles as long as they have the same temperature, and pressure.
- If they have the same number of particles, then the mass ratio is due to the mass of particles.

(Use this hypothesis for the relative masses of all atoms on the periodic table!)

Let us introduce you to the following 4 types of masses. You are going to have to know these by heart.

ATOMIC MASS:
The mass of 1 atom of an element in Atomic Mass Units (AMUs).
Ex/ Fluorine = 19.0 AMUs


FORMULA MASS:
All atoms of a formula of any ionic compound. So basically the masses of all the elements in a compound added together.
Ex/ Potassium fluoride.
K F
39.1 + 19.0 = 58.1 amu

MOLECULAR MASS:
Basically the same as formula mass EXCEPT it is regarding covalent compounds. YA DIG? So just simply add all of the masses of the elements in the compound. I know it sounds confuzzling, but it's really not that bad after The Smarticle Particles explain it to you.
Ex/ Carbon monoxide
C O
12.0 + 16.0 = 28.0amu

MOLAR MASS:
So um yeah, chemistry just gave us another confusing term that really isn't that complicated. It's essentially ANY atomic/molecular/formula mass, added and garnished with a g/mol.
Ex/ 1 mole chlorine = 35.5g/mol
1 mole fluorine = 19.0g/mol
....YA DIG?

AVOGADRO'S NUMBAAAAA
Okay. This number is really big. Like. You won't even know it until you see it. We. Mean. BIG.

6.022x10²³


This number also happens to be the number of particles in 1 mole of any substance.

6.022x10²³ particles/mol

This number allows for atoms and molecules to be counted!

Tuesday, November 9, 2010

Take your entrance exam for "Canada's Next Top Chemist"!

You should've seen this coming ever since we started this chapter. There is a test next class, which would be November 15th.

You are going to want to be comfortable with:

- Significant Figures
- Measurement + Uncertainty
- Scientific Notation
- Density
- Graphing
- Lab 2E
- Unit Conversions
- Formulas for Volume, Area, Density, and Percent Experimental Error.

Remember to bring a SCIENTIFIC CALCULATOR!


Sunday, November 7, 2010

Even Microsoft Excel Needs Some Love!

Microsoft Word always gets all the attention. When teachers, parents, students, frogs, dust particles and pop tarts need to type up some documents... who do they go to?? MICROSOFT WORD. It's always WORD. Doesn't anyone care about what Microsoft Excel has to say?


"I just feel so lonely- I know I can be confusing and hard to understand, but once you get to know me I'm really not that bad. *cries*" - Microsoft Excel


Do you see how negatively our behavior has affected Excel? That is why today we are going to learn more about Excel so it doesn't feel so lonely anymore. To be more specific, we are going to learn how to graph collected data, generate its equation, and determine the slope of the graph.


Just watch this quick video:


We suggest that you play around with a little and try to bling out your graph to make it more attrctive.

Friday, November 5, 2010

LAB DAY: Aluminum Foil and All That Jazz

DID YOU KNOW?

What many people don’t realize is that aluminum is practically 100 percent recyclable. It is extremely durable and can be reused over and over again. Aluminum foil is technically just as recyclable as aluminum cans. The problem is that aluminum foil is often dirtier, thus making it harder to recycle.




WOW. What a coincidence.

We just wanted to share chunk totally random and irrelevant information with you and WHAT DO YOU KNOW? It completely fits into what we were about to talk about today. (You know... the aluminum foil lab we did recently?)


ALRIGHT, now we're moving on to something thats relevant. OOOO. So basically what this blog entails is the summary of what we did in.....dun dun dun......LAB 2E.

Okay just kidding guys, it's not actually scary, so come out from under your blankets and lets get rolling.

The basic formulas you need to know are:
Density = Mass/Volume
Volume = Mass/Density
Mass = Density x Volume
Volume = Length x Width x Height (a.k.a thickness)
Height = Volume/(Length x Width)

Now I bet you're going WOAH THERE slow down my brain is imploding. Well I'm sorry, but we must move on.

BASICALLY, what we did in the lab was take 3 pieces of rectangular square-ish paper and measured each's length and width to the right amount of sig figs. (Refer back to our sig fig lesson if you are a confused child right now). We recorded them all on the chart with their absolute uncertainty.

NEXT we weighed the pieces of aluminum on a centigram scale.



Then guess what we did? We recorded it on our table!!!! Now, this is a mandatory step for if you don't record, then all your work will be lost which usually leads to tears. But dry your tears, because it is hard to read small print when you are crying and I must finish todays lesson.

After this, we had to find the exponential error. What is this you ask? Well lucky for you, I will tell you. Exponential error is the exponential growth of an error, or how an error can compound itself over time. The formula for this foreign topic is:

Exponential error = your measurement - accepted value / accepted value x 100%

NOTE: EXPONENTIAL ERROR MUST ALWAYS BE WRITTEN AS A PERCENT. If not, barney will come after you and continuously sing children songs until you become insane.............okay maybe not the worst that could happen would be you would lose marks. But nowadays, marks are EVERYTHING.

Lastly, we had to do some follow up questions. THIS is where the equations come in. Just make sure that when they ask you to find the thickness of the aluminum, it is actually the height, so use the height formula. YES, they trick you like that and YES they probably find it funny that students are pulling their hair out to try to figure out the thickness.

So I guess this is all for now folks. Hugs and hearts.


VISIT THIS LINK FOR A SPECIAL SURPRISE!

Tuesday, November 2, 2010

Density! Something Easy And Short. WIN

Density is relatively simple. Essentially, it is mass per unit volume. So technically, if you were given a mass in grams, and a volume in cm³, all you'd have to do is divide the mass by the volume. Here is an example:
Ex/ What is the density of 40g of copper, with the volume of 10cm³?
D=m/v=40g/10cm=4g/cm³. I understand this is confusing, (Blogger gives me limited features. Yes, excuses, I know, I'm full of them) but all you really have to do is divide a given mass by a given volume.

Ex2/ BUT BUT BUT BUT BUT. WHAT IF WE DON'T HAVE THE MASS OR VOLUME?!!!!! Oh gosh, I'm starting to hyperventilate just by the thought of it. I'm getting frantic too. BUT don't fear! All you have to do is switch things around here and there. What if you wanted to find the volume given the density and mass?
Since the general formula for density is d=m/v , using simple algebra, in order to find volume, we know v=m/d. Therefore, now all you have to do is plug the numbers in. I'm sure you all have learnt this skill in Math 10.


When something is more dense than another object, that object will sink. If something is less dense than another object, the less denser object will float on top of another. Oil and water is an excellent example. The oil will always float on top of the water no matter what, since oil is less dense than water. Here is a cool picture. YAY!

Monday, November 1, 2010

Meh...... So Which One Was Accurate?

Imagine you are back in Ancient Greece trying to measure your farm again. Fun! Now, when we take our time machine back and use our metre stick, we find out that the length of the farm is 25.87m. However back in Ancient Greece, you didn't have the luxury of the metre stick. So thus, we go back to using our armspans.



Let's just settle with 1 armspan=1m. You settle with the length as 26 armspans because... Well, you counted 26 armspans. Now let's say we now travel to the future and use some sort of metre-sticko-whiz. And the number comes out as 29.283928347817341203497m. So which is accurate and which is precise? Here is your answer:

When something is accurate, the value/number is CLOSE to the actual measurement. So essentially it is the correctness of a measurement. However if something is precise, it is a reproducible measurement, and usually has more significant digits.



So what's the answer? 26 armspans is accurate, and 29.283928.......m is precise. An example of an accurate YET precise reading would be 28.8671023934871m.

NEW TOPIC!
Like how everything in this world isn't perfect, no measurement is perfect. Which concludes that no measurement is exact. It is only when we count (tangible) objects, we get exact measurements. For example, 30 people in the class. We cannot have 29.5 people, can we? That would just be awkward.

Absolute uncertainty is the expressed uncertainty in a certain measurement. So how on earth do we do something like that? Luckily, there are two methods.

Method number glorious one. Make at least three measurements when measuring whatever. Then calculate the average of all your measurements; The absolute uncertainty is the largest range between the lowest measurement measured and the highest. However there is one catch--You MUST throw away, crumble up, burn to ashes, sautee, and sprinkle over Donald Trump's combover, numbers that do not "belong". Let's say you have four measurements. 1.) 16.88 2.)19.89 3.)16.50 4.)16.94. Which is the odd one out? Obviously measurement number two must be discarded.

Method number two. Just simply determine the uncertainty of each measurement you make. Just use the eyes that God gave you, and use them to the best of your ability, and measure as precisely and accurately as you can. You should estimate at least to the 10th of a fraction of each increment on a measuring utensil. For example if a test tube went up in increments of 1, your uncertainty would be +- 0.1.

RELATIVE UNCERTAINTY This HAS to be expressed as a percent. (I learnt it the hard way by getting a mark off my assignment). The number of sig figs in a measurement indicates the relative uncertainty. Remember that the number of significant figures all certain digits plus all uncertain digits. There is a general formula for relative uncertainty: (Absolute uncertainty/estimated measurement) x 100