Chemical Reactions Chapter 10

10.1 Reactions and Equations The process by which the atoms of one substance are rearranged to form different substances is called a chemical reaction. Subscript Yield CH4 + 2 O2  CO2 + 2 H2O Reactant Product

A chemical reaction has taken place when: -Temperature change -Color change -A gas is produced An odor is produced Precipitation is formed Matter cannot be created nor destroyed. Coefficients are added to have equal amounts of reactants as products.

Symbols + (a plus sign) separates two or more reactants or products  (an arrow) separates reactants from products. (s) = solid state (l) = liquid state (g) = gaseous state (aq)= aqueous state or ( in water solution)

Word equations Example: “ Solid iron and chlorine gas react to produce iron(III) chloride solid” Skeleton equations= changing the word equation into symbols Example: Fe(s) + Cl2  FeCl3 (s) Don’t forget about your diatomic molecules= H2 N2 O2 F2 Cl2 Br2 I2

Common mistakes Don’t forget to swap and drop Don’t forget roman numerals= the charge Fe (III) = Fe+3 If it ends with an –ide its bonded Ex: Hydrogen Chloride= HCl If it end with an –ine its just the element Ex: Chlorine= Cl2

Examples Solid carbon and solid sulfur decompose to make carbon disulfide. Skeleton=

Examples Hydrogen gas and bromine gas combine to produce hydrogen bromide gas. Carbon monoxide gas and oxygen gas combine to produce carbon dioxide gas.

Example Potassium chlorate(s)  potassium chloride(s) + oxygen (g) On your own do questions on pg 875 section 10-1 questions 1-8