Week 2 has now gone up in flames... on to Week 3!

Week 3 Resources/ Assets
Updated September 7, 2018
This is your landing page for announcements and current news for your chemistry class. Please check this page often.

Physical and Chemical Properties of Matter
This last week through reading, class lecture, and homework questions, you should have learned that all matter has both physical and chemical properties. Recollect that physical properties are those we can readily measure or readily observe, such as:
  • boiling point
  • freezing point
  • density 
  • color
  • odor
  • magnetism
  • specific heat
to name a few. Whenever we describe chemical properties, we are interested in fundamentally different things, such as how the sample of matter reacts with other atoms or molecules. As an example, iron has the chemical property of reacting with oxygen gas to form rust - whereas gold does not.

Lab 2 - Separation of a Mixture
When chemists are tasked with the problem of identifying chemicals within an unknown mixture (such as a contamination spill in a lake), they take advantage of the differing physical properties of the chemicals within the mixture (if indeed the contamination released many chemicals) in order to separate them from one another.  In the same way, we will do this next week when we separate a mixture of pebbles, sand, and salt by taking advantage of their differing physical properties.
  • the pebbles will be separated from other components within the mixture by virtue of their size, by using a sieve (colander)
  • after adding water to the salt/ sand mixture and mixing thoroughly, the sand will be removed from the salt water using gravity filtration
  • finally, the salt will be removed from the water by means of crystallization in an evaporating dish, by boiling off the water
You will perform in class on Tuesday what chemists do all over the world - they separate constituents within a mixture, by taking advantage of the differing physical properties of the constituents themselves!

Extra, Extra... Read all About it!
I didn't really get the chance to cover the last section of Chapter 2 - Section 2.4 -  Chemical Reactions. Please make sure you read this section and understand it. The concept of great interest here is the Law of Conservation of Mass. Simply put: in any chemical reaction, mass is neither created or destroyed, but is conserved. If 16 grams of oxygen gas reacts with 2 grams of hydrogen gas, you will obtain as a result, 18 grams of water. The total amount of mass in the reactants always equals the total amount of mass in the products.

Looking Ahead to Week 3/ Chapter 3
For Chapter 3, the focus will now turn to measurement: how we accurately measure and record chemical information. I will not spend any time in class at all on how to deal with scientific (exponential) notation - this is a skill you should have acquired in pre-Algebra classes, but if you need a quick review on how to manipulate and write numbers in scientific notation, I have attached several links to Tyler Dewitt YouTube videos at right. Refer to these only if you need to. Finally, you should make sure this week that you know how to key exponents in your calculator.

We will spend quite a bit of time during the next few weeks on topics related to error. Unfortunately, error is a part of any measurement we make, so we have to learn how to record data values reflecting these errors, or at the very least reflecting the limitations of our measuring devices, whether they be rulers, graduated cylinders, or scales. This is where significant figures comes into play. When you return on Tuesday, we will perform the Separation of a Mixture lab, along with the Significant Figures lab. 

Finally, if you think you would learn better by watching a video lesson on significant figures rather than reading in the textbook, please take advantage of the other Tyler Dewitt videos at the right. Watch these only if you want to.

So, young chemists, please make sure you do the following by:
Tuesday's class - September 11th
  1. ​Due at beginning of class: all of the assigned Chapter 2 problems (linked right). Note that I have also attached a link to the Chapter 2 Answer Key. Please make sure you do your best to answer these questions by yourself first, then refer to the answer key.
  2. Due in class: completed Beaker and Flask Accuracy Lab
  3. Due in class: completed Beaker and Flask Accuracy Lab Quiz (linked right).
  4. Print out, read and bring to class the Separation of a Mixture Lab (linked right).
  5. Print out, read and bring to class the Significant Figures Lab (linked right). I will supply all materials you need for it, but bring your calculators.
  6. Prepare for Quiz #3, covering Chapter 2.

Scientific Notation videos by Tyler DeWitt (optional)

Significant Figures videos by Tyler Dewitt (optional)