Friday, August 27

The focus of Friday's class period was chemical safety. We went over the Student Safety Contract in our Survival Packet and discussed a variety of safety-related issues.

Mr. H talked about the need for safety-consciousness when working around flames. One hazard involves working with volatile and flammable substances when there are flames at the same lab table. A volatile liquid is a liquid which vaporizes quite easily. A flammable substance is one which catches on fire when exposed to a flame. Mr. H did a demonstration to illustrate the need for caution. He had a flask of hexane - a volatile and flammable liquid. He shook the flask to more fully saturate the air in the flask with the vapors of the volatile liquid. He then pulled the stopper off the flask and tipped it slowly over a long metal incline. Being heavier than air, the vapors of hexane fell down  the ramp towards a lit tea-light at the bottom of the ramp. Upon reaching the tea-light, the vapors immediately caught on fire. The flames traveled up the ramp following the vapors towards the flask. Mr. H quickly pulled the flask of liquid hexane away to keep it from igniting. The demonstration underscored the importance of paying attention to what is happening when working around flames.

There are other hazards of working around flames. Most importantly long hair and loose clothing can catch on fire. Mr. H showed us the location of the fire blanket and the safety shower in the classroom. A fire extinguisher is also in the room; it is to be opertated only by Mr. H.

Mr H re-emphasized the importance of goggles with a demonstration.  He showed us a stryofoam mannequin which had been repeatedly squirted with acetone (see picture at left). He then took an acetone bottle and squirted the mannequin on the side of the neck. The acetone carved out a 2-inch wide channel in the mannequin upon contact (see picture at right).

Mr. H also discussed the use of the eye wash. The eye wash is used if you experience a chemical splash or burn in your eye. You should wash your eye for about 15 minutes if you encounter such an accident. Use your fingers to hold your eye open while washing thoroughly with water. If you have contacts in (which isn't a wise idea), first rinse a couple of minutes and then remove them.

Mr. H did a demonstration of how to smell a chemical substance. When smelling a chemical substance, you should NOT close a nostril and snort the vapors into the open nostril. This is a very bad idea and is almost certain to lead to a headache by the end of the period. The proper way of smelling a chemical substance involves wafting it towards your nose. Often times we will use a fume hood when working with abnormally noxious substances. The fume hood is in the back of the room.

We watched a safety video which described and explained a variety of hazards of working with chemicals and in a chemical lab. Precautions were discussed and clearly portrayed.

Finally, we were given some time to put our names on our goggles and place them in the Period 3 drawers. And we were given some time to read the Student Safety Contract.

The period ended with Mr. H giving us a handout and discussing the idea of our class blog. The class blog is a collective endeavor of the students in our class to chronicle our journey through chemistry. The blog will become our book, written by us and for us. If we do a good job, it will become a personalized version of our textbook. We will be able to use it as a study tool and a reference tool. Concepts will be explained, principles will be discussed and the mathematics will be demonstrated. As we prepare for our quizzes and tests, we can reference the blog as a study tool.

Each day, a different student will be assigned the task of being the scribe. The scribe is responsible for putting together the blog post for that day. The scribe must do all the writing and place the blog as a post in Blogger. Any variety of items can be included in the post. Examples include scans of completed packet pages, photos taken with our camera phone or camera, video from a Flip video recorder or camera phone or camera, YouTube videos watched in class, links to useful websites, references to textbook pages, etc. The main idea that each scribe must keep in mind is that it is their responsibility to completely and fully document that day of our journey through chemistry. When we all do our best, we will be able to produce a product that we can be proud of and will want to use.