Chemical Changes Monroe

What are the parts to a chemical formula? Coefficient Atoms Subscripts

What are the parts to a chemical formula? Coefficient ~ Tells the number of units of compound. It always goes on the front. Subscripts ~ Element Compound

What are the parts to a chemical formula? Coefficient ~ Tells the number of units of the compound. It always goes in the front. Subscripts ~ Tells the number of atoms in the compound. Subscript means “below writing”. Element ~ Compound

What are the parts to a chemical formula? Coefficient ~ Tells the number of units of substance. Subscripts ~ Tells the number of atoms in the compound Element ~ Tells the type of atom in the compound Compound

What are the parts to a chemical formula? Coefficient ~ Tells the number of units of substance. Subscripts ~ Tells the number of atoms in the compound Element ~ Tells the type of atom in the compound Compound ~ Tells what combination of atoms, chemically combined, you are looking at.

What are the parts to a chemical formula? Coefficient ~ Tells the number of units of substance. Subscripts ~ Tells the number of atoms in the compound Element ~ Tells the type of atom in the compound Compound ~ Tells what combination of atoms, chemically combined, you are looking at.

What are the parts to a chemical formula? Coefficient ~ Tells the number of units of substance. Subscripts ~ Tells the number of atoms in the compound Element ~ Tells the type of atom in the compound Compound ~ Tells what combination of atoms, chemically combined, you are looking at. C 8 H 10 N 4 O 2 This is a compound

What are the parts to a chemical formula? Coefficient ~ Tells the number of units of substance. Subscripts ~ Tells the number of atoms in the compound Element ~ Tells the type of atom in the compound Compound ~ Tells what combination of atoms, chemically combinded, you are looking at. C 8 H 10 N 4 O 2 This is a subscript

What are the parts to a chemical formula? Coefficient ~ Tells the number of units of substance. Subscripts ~ Tells the number of atoms in the compound Element ~ Tells the type of atom in the compound Compound ~ Tells what combination of atoms, chemically combined, you are looking at. C 8 H 10 N 4 O 2 This is an element

What do they tell us? They tell us how different chemicals will combine with each other.

O 2 + H 2 H 2 O + heat What is very, very wrong with this equation?

What do they tell us? They tell us how different chemicals will combine with each other. O 2 + H 2 H 2 O + heat It is NOT balanced. Oxygen21 Hydrogen22

What do they tell us? They tell us how different chemicals will combine with each other. O 2 + H 2 H 2 O + heat O 2 + 2H 2 ---> 2H 2 O + heat Oxygen Hydrogen44 (Always multiply the coefficient and the subscript)

Some important things to remember. 1.The stuff on the left is the reactants 2.The stuff on the right is the products 3.The total amount of stuff on the left MUST equal the amount of stuff on the right, because of the law of conservation of mass.

Some important things to remember. 1.The stuff on the left is the reactants 2.The stuff on the right is the products 3.The total amount of stuff on the left MUST equal the amount of stuff on the right, because of the law of conservation of mass. 4 g of Hydrogen + 32 g Oxygen = 36 g Water O 2 + 2H 2 ---> 2H 2 O + heat

Balancing equations 1.Solid magnesium burns with gaseous oxygen to make solid magnesium oxide. 2.Step one is to write out the sentence with chemical symbols, according to what actually happens. Mg (s) + O 2(g) --> MgO (s) + energy Step two is to choose coefficients that balance the number of atoms on each side, but never, never ever change the subscripts. If you change the subsript, you are saying that something else is being made. 2Mg (s) + O 2 (g) --> 2MgO (s) If there is no coefficient, or subscript, it is a “one”.

Hydrogen gas burns with oxygen to make liquid water, and excess energy. Hydrogen gas and oxygen gas are always O 2 and H 2.

H 2(g) + O 2(g) ---> H 2 O (l) + energy

Hydrogen peroxide (H 2 O 2 ) liquid decomposes into oxygen gas and water, if energy is added to the equation.

H 2 O 2 + energy --> H 2 O + O 2

Hydrogen peroxide (H 2 O 2 ) liquid decomposes into oxygen gas and water, if energy is added to the equation. H 2 O 2 + energy --> H 2 O + O 2 2H 2 O 2 + energy --> 2H 2 O + O 2

Butane gas (C 3 H 8 ) burns with oxygen gas to make carbon dioxide gas and liquid water, and gives off energy.

C 3 H 8 + O 2 ---> CO 2 + H 2 O + energy

Butane gas (C 3 H 8 ) burns with oxygen gas to make carbon dioxide gas and liquid water, and gives off energy. C 3 H 8 + 5O 2 ---> 3CO 2 + 4H 2 O + energy

Photosynthesis is when sugar, C 6 H 12 O 6 and O 2 combine to make carbon dioxide and water. C 6 H 12 O 6 + O 2 --> CO 2 + H 2 O

Photosynthesis is when sugar, C 6 H 12 O 6 and O 2 combine to make carbon dioxide and water. C 6 H 12 O 6 + 6O 2 --> 6CO 2 + 6H 2 O