Friday's class was full of fun and learning! Now my job on this Sunday evening is to re-word my knowledge from last class onto this blog. I love blogs, they are a hobby of mine, that is for sure!
Anyway, last class we learned about a few basic laws, including the Law of Multiple Proportion and the Law of Definite Composition. The Law of Multiple Proportion is when at least 2 compounds with different amounts of the same element can be created. The example from the class was Co2->C2O4->C3O6... and so on. The Law of Definite Composition is when a compound will always remain a compound, no matter what the circumstances are. The class example was H2O, it will always be H2O no matter if it is a solid, liquid, or gas.
Moving on, we learned about the heating/cooling curve of a pure substance. Now I could be fancy, and make a chart or grid of some sorts, but lets go old school here, and use our imagination. Now imagine a grid, with the X Axis as Time/Minute, and the Y Axis as Temperature in Celsius. Now picture the letters A to F, resembling points in a stair like fashion, towards the top right corner of the grid. Got it? Great. Now point A is on the Y Axis, and it is a solid state at any temperature below the melting point. A solid is packed very tightly together and does not move a whole lot. Now between points A and B is a line, and that line shows how the Kinetic energy increases, the molecules move faster, and the temperature increases. At point B, the substance remains a solid, but is beginning to melt. The line B-C is a mixture of both a solid and a liquid. It can be either Freezing or Melting, depending on whether the substance is being heated or freezing. The temperature remains constant but it is melting into a liquid at the same time. The substance's particles are becoming more spread out and moving at a faster rate. Now point C. Point C is officially what humans call, a liquid. If it is H2O, then it is water. Cool stuff eh? I thought so. Moving on, C-D is the liquid being heated and the molecules again acquire more heat and speed via Kinetic Energy. Point D exists in a Liquid State. The particles in the substance have enough Kinetic Energy to man up and overcome the adversity of the attraction of particles, so it is not a solid. In fact it is on its way towards being a gas. Now line D-E can either be Evaporation (liquid into gas), or Condensation (Gas to Liquid). Even though the line is in between a liquid and a gas, the temperature remains unchanged. In fact the heat energy is absorbed is not to change the temp, but rather the speed of the molecules. This consistent temperature is known as the boiling point. Now point E is strictly a Gas. Plain and simple. Finallllllllllly, is the line E-F. E-F shows that the gas particles continue to absorb energy and move faster, leading to another increase in temperature. After that, the gas may transform into a solid (Sublimation). If it were Solid to Gas, it would be Deposition. Now for you uncool, mindless, unimaginative people, here is a graph to show all that I explained beautifully.
Textbook Pages 25-34
-The temperature at which matter changes from a liquid to gas is called its boiling point
- A mixture is two or more kinds of matter that have separate identities. They can be divided into different components that are different from each other.
-By classifying matter, you develop a better understanding of it
-Mixtures that are uniform(the same) throughout are called solutions.
Distillation is a procedure used to separate solutions into separate components.
-Changes that produce new substances with different properties are called chemical changes
-Physical changes are changes that can be reversed to obtain the original substance easily. They don't produce new substances.
-Decomposition is the type of change when one kind of matter splits into two or more kinds of matter.
-Electrolysis is a procedure where an electric current is passed through a substance, causing it to decompose into new substances.
-Decomposition and distillation appear similar, but study reveals that they are actually fundamentally different processes.
-Pure substances that can be broken down into new matter are called compounds.
- Compounds are composed of pure substances called elements which cannot be broken down.
-109 known elements
-All matter on Earth made up of 85 elements
-Just 8 of these make up 99% of earth's crust
Law of Definite Composition:
Mixtures can have almost any composition that is desired but compounds will have a definite composition.
e.g. The volume of H2 obtained from water is always twice the volume of O2 obtained.
Law of Multiple Proportions:
Two or more compounds with different proportions of the same elements can be made.
- A particular compound = not more than 1 proportion like a mixture; same elements can form different compounds though, that have different make up but having different composition from the others.
Pg 36-39
-Matter is made up of atoms
-Macroscopic observations are observations you can make by seeing, feeling or smelling.
-The word atom means "smallest piece of something"
- Temperature increases- movement becomes faster and stronger and breaks forces that hold them together as a solid, and become a liquid, and the particles then flow past each other.
-Temp. of a liquid reaches boiling point, the liquid becomes a gas b/c particles move with such energy and force they break forces of attraction and move freely
- Compounds can be solids, liquids or gases
- One atom of an element*----One molecule of a compound
-Molecules are two or more kinds of atoms combined.
-Ions are particles that have an electric charge
Copper (II) Sulfate Pentahydrate
