Showing posts with label RachelS. Show all posts
Showing posts with label RachelS. Show all posts

Friday, December 14, 2012

Metal Reactivity Lab

Hey guys! So today in class we completed the Metal Reactivity Lab which had some pretty cool reactions in it. We started off the class, however, with watching some videos about Metal reactions and how the place on the periodic table corresponds with how strong a metal reacts with water (H2O). Both videos showed some pretty cool explosions and in case you want to watch it again, the episode of Braniacs is below even though everyone knows the explosions were fake :/

After the videos, we proceeded on with the lab. We began by taking a well plate and filling three wells with H2O, three wells with phenolphthalein, and three wells with HCl. Next, we took three pieces of magnesium ribbon, three pieces of aluminum ribbon, and three pieces of calcium metal and put one piece of each in their own wells in each of the liquids. We observed the reactions that took place and recorded them in a data table that will go into our lab books. It is a pretty straight forward lab and hopefully you understand the main idea that as you move down a column on the periodic table, elements become reactive in contrast to when you move across a period and the metals become less reactive.  The images below show what happened in the the experiment. There are no picture of the elements in phenolphthalein because no reactions occurred.  
Magnesium in HCl
Calcium in HCl
Aluminum in HCl
Aluminum in H20
Calcium in H2O
Calcium in H2O
Magnesium in H2O

I hope you guys have a good weekend and I would just like to remind you that the Alternate Universe Periodic table is due Monday along with this lab. The test is Tuesday and the Webassigns are due that days as well! 

Next scribe will be Chris!! Don't worry it's not that bad :P

Tuesday, October 2, 2012

Percent Composition/ The Bubble Gum Lab

What's up guys! I hope you all enjoyed today as we stepped back into 90s and learned what NOT to wear to school by looking at some pretty ridiculous outfits (my clothing was a fine example). But in all seriousness, the bubble gum lab. Haha just kidding it was pretty fun to chew gum and listen to music in class. :P

Okay. So we started off class today by reviewing Avogadro's number (6.02x10^23) and how to use it as a conversion factor. SEE PICTURE BELOW



This is a pretty handy dandy model to remember so make sure you remember this!! 


PERCENT COMPOSITION
Today, we learned how to find the percent composition of an element and it's super simple. First, you have to find the molar mass of an element. For example, CuBr2 would be 223.55 grams. Then, you take the mass of each individual element and divide that by the total mass. For example, Cu would be 63.55 divided by 223.55. You then take that number and multiply it by 100 to find the percentage. SO EASY! You do that with the rest of the elements and that's it! 





The Lab
The next thing we did, was the amazing bubble gum lab. The goal is to find the % sugar in a piece of bubble gum and write an empirical formula for it. (GxSy) REMEMBER G is a FICTIONAL symbol for Gum. Get it? G for Gum? And S is a FICTIONAL symbol for Sugar. S for Sugar? Yeah, I know it's super clever. But the mass of the GUM is 513 g/mol and mass for SUGAR is 342 g/mol.

Basically we took a piece of gum, weighed it, chewed it, and weighed it again. Super simple I know. However, we then need to calculate the mass of the sugar in the gum, the gum before the chewing, the gum after the chewing without sugar, the % composition of the sugar, and find how many moles of sugar and gum there are. We needed to use the data and measurements obtained from weighing the gum to find that. Finally, we have to calculate the ratio between the moles of sugar to moles of gum which will then be the empirical formula. AKA the answer.

Reminders
  • Hydrate lab due tomorrow
  • Bubble gum lab due Thursday
  • % Composition worksheet due tomorrow
  • Test on Friday!
  • Do your WEBASIGNS!!!
  • DRESS AS YOUR FAVORITE 90s CHARACTER SO THE GENIE COMES OUT!!
NEXT SCRIBE WILL BE: BRAM!!!!!