Warm Air vs. Cool Air

Warm air is less dense than cool air, because warm air raises, while cool air sinks.  Also warm air molecules move faster than cool air molecules.  Humid air weighs less than dry air, because the water vapor is less dense.

Cocaine

 

Caffeine

Limiting Reagents

To figure out how many Quarter Pounders you can make, first you need to figure out what the formula is.  Then you  have to find out which ingredient is the limiting reagent, because that is what determines the what your final yield will be.

2H₂+ O₂ → 2H₂O   8.5g- hydrogen      40.2g- oxygen

hydrogen is the limiting reagent

Types of Reactions

Acid - Base
Precipitation
Gas Forming
Redox

Lab 4 Reflection

1.  I was surprised at the color changes that took place when we mixed two different substances together.

2.  Some observations that showed a chemical reaction had taken place were color change and temperature change.

3.  In the precipitation reactions all of the end products were solids, but when we did the molecular substances we got different results.  With the combination of sulfuric acid and sodium carbonate it resulted in carbon dioxide (a gas) and water (a liquid) being produced.

4.  When salt is poured into water it dissolves, so the sodium and the chlorine separate from each other.
NaCl (crystals) + H2O = Na+ (aq) + Cl- (aq) + H2O (L)

Assignment 6

The two main topics from class were Coulomb's Law and ionic compounds.
sodium metabisulfite- Chex Mix
salt / NaCl- Cookies
calcium carbonate- Chex Mix
trisodium phosphate- Chex Mix
sodium bicarbonate- Granola Bars

Assignment 5

We learned about atoms and what makes them up.  In the center every atom has a nucleus, which is where most of the atom's mass is actually located.  The nucleus consists of protons, which have a positive charge, and neutrons, which have no charge.  The rest of the atom is made up electrons, which have a negative charge.  Electrons move freely and are not confined to a certain space.

Assignment 3

Topics:
       - Temperature
       -  States of Matter
       -  Density
Absolute temperature scales can only have positive numbers, while relative temperature scales can include negative values as well.  Both the Celsius and Fahrenheit scales are relative, but the Kelvin scale is absolute.  With relative scales the values are reference points such as the freezing and boiling point of water.

Assignment 2

1. The periodic table of elements.
2. Matter and how it relates to chemistry.
3. Chemical Reactions

I thought the experiment with the balloons was interesting.

A couple ways to tell if there has been a chemical reaction if there is any odor change or color change.

I liked being able to look at the notes on my computer.

Assignment 1

In the engineering field there are many instances when a knowledge of chemistry is essential.  There are specific branches of engineers that have an emphasis on chemistry.  Combustion engineers, for example, have a large focus on chemical reactions.  Chemical engineering revolves around chemistry and how it can be uses to convert materials into more useful forms.

A very important molecule to the engineering field is carbon.  Carbon fibers are very strong, cost effective, and are used in multiple ways in the engineering field.  Often it is used to strengthen things like concrete, steel, and cast iron.