1/30/14 Molecular Geometry

Mrs. Friedmann started off class by telling us what our homework is for tonight. We have 2 web assigns due at 11:59, another VSEPR handout to do, and we should check moodle for the key to the worksheets we did yesterday. Plus, we have another quiz tomorrow which will be on all the stuff we've been learning about molecular geometry.

In class, Mrs. Friedmann had us finish the VSEPR chart that we started yesterday. This is similar to what we ended up with:




 We are supposed to have this memorized for tomorrow, and Mrs. Friedmann suggested 2 ways. We can either memorize the VSEPR code (ABE) and memorize all the corresponding shapes. . .
OR we can try to visualize what shape the molecule should be just by using our knowledge of the number of clouds and how that number will impact the formation of the molecule. Mrs. Friedmann suggested the latter.

After we finished up the chart, Mrs. Friedmann introduced something called Wedge and Dash Drawings to us, which is a technique for drawing 3-D molecules more clearly. The way it works is that you either use a normal line like this ___ to represent 2-D bonds, a wedge to represent the bonds that stick out towards you, and a dashed line like this - - - to represent the bonds that stick away from you. It's difficult to explain with words, so here's an example:
  It's just an optional, easier way to draw 3-D shapes.

And that's all, so. . . good luck on the quiz everybody!


The next blogger is Brandon Moy

Lab Safety

8/23/13 Scribe Post Author: Lauren B

At the beginning of class, Ms. Friedmann briefly covered all the need-to-knows of blogging such as what an ideal post should look like and what to do if we have a lab the day we're supposed to post (just blog for the next day). After that, we finished watching the lab safety video, and Ms. Friedmann gave us a little demonstration of her own about what not to do with the squeezy bottles, plus a cool example of why we should be careful around flammable chemicals.

Lab Safety Video Overview:

• Dressing:
• Avoid loose clothing - the ideal outfit is something that covers the majority of your skin but is fairly tight fitting
• Long pants and closed shoes are preferred but shorts and sandals are okay as long as you're careful
• Tie up long, loose hair
• Remove hand jewelry
• Protect hands by wearing gloves when possible
• Always wear safety goggles during lab (especially if you have contacts)
• Behavior:
• Don't fool around (for fairly obvious reasons)
• Don't leave bags and belongings laying in the middle of aisles where they're probably going to get tripped over
• Don't apply makeup in lab
• Don't eat or drink in lab
• When pouring something into a burette, keep the burette at eye level
• Emergencies:
• If cut, wash wound with clean water and dry. Let teacher bandage you and go to nurse immediately
• If chemical gets on hands, wash immediately in sink
• If chemical gets in eyes, wash in eyewash fountain for at least 15 minutes
• If strong chemical gets spilled on you, strip off quickly and rinse body in shower (this probably won't be necessary in our class, but for future reference. . .)
• Should a small fire occur in a test tube, cover it with a lid. If the fire's bigger, let the teacher take care of it with the fire extinguisher. If the fire's huge, it would probably be a good time to call the fire department and get out
• If clothing catches on fire, put out in safety shower. Or (if the shower is too far away) have person stop, drop, and roll. Then cover them with the fire blanket

Words of Wisdom from Ms. Friedmann:


As tempting as it may be, try to resist the urge to squirt your friend in the back with a squeezy bottle, because, as hilarious as it would be with water, you can't know for sure you won't accidentally grab the wrong bottle :)

Hexane Demo:
Similar to how she ladeled the carbon dioxide out of her ''zombie bubble" tank and extinguished a candle by pouring the contents of the spoon over it, Ms. Friedmann was able to demonstrate a similar experiment with the gas from a highly flammable chemical known as Hexane.
                                                                 
   First, she lit a small candle at the base of a long, tubelike instrument angled downward. She then picked up a glass beaker with about an inch of liquid Hexane at the bottom, and swirled it around until she was sure some fumes were being released. She then tilted the beaker just enough so the Hexane fumes would come out from the beaker (and not the liquid) and travel all the way down the tube to the candle. When the Hexane reached the flame, fire burst up, and trailed all the way up to the very top of the tube.
That's all!


The next scribe post author is Suvd Davaadorj