State the Law of Conservation of Mass and explain what it means for a chemical reaction.
The total mass of the products formed in a reaction is equal to the total mass of the reactants. The number and type of atoms must be the same on both sides of an equation.
What are the four state symbols used in chemical equations
Solid (s), Liquid (l), Gas (g), Aqueous (aq)
What are the rules for balancing a chemical equation?
You can only add a large number (coefficient) in front of a formula
You cannot change the small numbers (subscripts) within a formula changing
as this creates a different substance.
The total number of each type of atom must be equal on both the reactant and product sides.
If 33.6 g of magnesium carbonate decomposes to create 16.0g of magnesium oxide, how much carbon dioxide is produced?
Mass of Reactants = Mass of Products
33.6g = 16.0g + (x)g
33.6 - 16.0 = 17.6g
What is an element?
A substance made of only one type of atom.
What is an atom?
The smallest part of an element that can exist.
What is a compound?
A substance made of two or more different types of atoms chemically bonded together in a fixed ratio.
What does a chemical formula tell you?
The ratio of atoms of each element in a compound (e.g. in H2O, the ratio of H:O is 2:1)
What is a molecule?
Two or more atoms chemically bonded together. These can be the same element (like O2) or different elements (H2O)
What are reactants and products?
Reactants are the substances you start with (left side). Products are the new substances made (right side).
Why must symbol equations be balanced?
To show that there is the same number of atoms of each element on both sides of the equation.
