What are Chem. Reactions and Writing Chem. EquationsBy: Ben Carroll, Xian Apdian and Peter Cao

Chemical Reactions• Chemical reactions take place everyday• Digestion in your body relies on chemical reactions.• Photosynthesis – occurs in plants to grow.• Both are necessary to sustain life.

• Reactants Products• Proposed by John Dalton.• Reactions break old bonds and form new ones that hold the atoms together.• Atoms are never created or destroyed.• Theory explains Law of Conservations of Mass.

Chemical Reactions (cont.)

• The number of atoms in the product are the same as the ones in the reactant.

• Chemical reactions can be described in many ways.• Rusting iron(III) oxide• Hydrogen Peroxide water + oxygen•Methane + oxygen carbon dioxide + water

Fun Fact for Chemical Reactions• Without chemical reactions we wouldn’t have

important products that keep us alive or healthy.

Interactive Question• Name 2 chemical reactions that make daily life

possible.

A.

PhotosynthesisB. Digestion

Writing Chemical Equations• How to write a chemical equations.• An arrow separates the formulas of the reactants from the formulas of the products (Reactants Products)

> Examples: Fe + O2 Fe2O3

• Skeleton equations – A chemical equation that doesn’t indicate the relative amounts of the reactants and products.

• Physical states can be represented by…Solid (s)Liquid (l)Gas (g)Acid (aq)

• Example: Fe(s) + O2(g) Fe2O3(s)

Writing Chemical Equations (cont)

• Catalysts – a substance that speeds up a reactions without being used up (it isn’t a reactant to the product)• Example: H2O (aq) H2O (l) + O2(g)

•MnO2 is the catalyst for Hydrogen Peroxide.

MnO2

Interactive Question

Give the correct formulas that would form the following products1) H2O

A. H+O

C. H2000+O4000

B. H2+O2

D. H3+O3

Fun Fact for Writing Chemical Equations• Some major professions that need to know how to

write chemical equations…• Chemical Engineering• Forensic Science• Biology

Homework• Identify the reactants and products of the

following chemical reactions.• (Reactants Products)

Example: Sodium + Chlorine Salt• Hydrogen and Oxygen merges to form water.• Sucrose is formed by Carbon, Hydrogen, and Oxygen.• When Nitrogen and Hydrogen are contained together,

they combine and form Ammonia.

The End• Sorry that was such a boring presentation• Enjoy a picture of baby Mr. Sweeten