Where are we going with this? This page will give the ability to demonstrate an understanding of the law of conservation of mass through the use of particle diagrams and mathematical models.
The Law of Conservation of Matter
This is far more important than it is difficult!
This is far more important than it is difficult!
This is pretty simple… No, really.
Getting a solid understanding of this concept is extremely important in progressing successfully through chemistry. Beyond just memorizing the words, you should try to ground yourself in the ideas and principles.
The Law of Conservation of Matter is one of the two Laws of Conservation. One has to do with energy. The other has to do with matter. Ignoring the fact that matter can become energy and all that… relativity stuff and E=mC2…
The Law of Conservation of Matter: matter can neither be created nor destroyed.
So what?
Chemistry… Conservation of Matter… moles… grams… There has to be a connection!
There are. A couple…
In any chemical reaction:
- The total mass of the reactants is equal to the total mass of the products.
- The total number of atoms among the reactants is equal to the total number of atoms in the products.
- The individual numbers of each type of atom in the reactants is equal to the individual numbers of each type of atom in the products.
Let's make this page a little longer and discuss.
The total mass of the reactants is equal to the total mass of the products. This means that if you have some number of grams of one thing and some other number of something else, then when they react, the sum of the masses of whatever is produced will not change. If you start with 2 grams of hydrogen and 16 grams of oxygen, you'll end up with 18 grams of water.
The total number of atoms among the reactants is equal to the total number of atoms in the products. Same idea here… If you have 2 hydrogen atoms and 1 oxygen atom to begin with, you will end up with 3 atoms, total. And since the individual numbers of each type of atom in the reactants is equal to the individual numbers of each type of atom in the products, then you will have exactly 2 hydrogen atoms and 1 oxygen atom.
Let's add one more idea…
The number of moles does NOT add up. That water reaction we've been talking about…
You can start with 2 moles of hydrogen and 1 mole of oxygen…
2H2 + 1O2 --> 2H20
… and end up with 2 waters.
The number of moles did not "add up"!
No comments:
Post a Comment