CHEMICAL REACTIONS & WRITING CHEMICAL EQUATIONS. JAKE T, JOSH, GABI

7.1 CHEMICAL REACTIONS All chemical reactions involve changing substances. Reactants- substances that are started with Products- substances that are ended up with Reactants products Endothermic reaction- a reaction that uses up energy from its environment. Ex. Instant cold packs Exothermic reaction- a reaction that gives off energy to its environment. Ex. Heating pad

LAW OF CONSERVATION OF MASS Mass and atoms cannot be destroyed nor created. Only changed.

WHICH SIDE OF A CHEMICAL EQUATION HAS THE REACTANTS? 4Fe + 3O 2 2Fe 2 O 3

WORD EQUATIONS Reactants are written on the left and products on the right. Ex. Methane + OxygenCarbon dioxide + water Hydrogen peroxidewater + oxygen Iron + oxygen iron (III) oxide

CHEMICAL FORMULAS AND EQUATIONS Chemical equation- a shorthand method used to show the number and type of atoms present in the smallest representative unit of a substance. Skeleton equation- a chemical equation that does not indicate the relative amounts of reactants and products. Ex. H 2 O 2 (aq) H 2 O (l)+ O 2 (g)

WHAT SYMBOL DOES THIS REPRESENT? Delta Heat Cool Dissolved in water

CATALYST AND INHIBITORS Catalyst- Used to speed up a chemical reaction. Inhibitors- Used to slow down a chemical reaction. -Its formula is written above the arrow in the chemical equation. Examples of CatalystsExamples of Inhibitors PlatinumFormaldehyde Potassium Permanganate Acetanilide Manganese DioxideSalt (NaCl)

Is vinegar a catalyst or an inhibitor? Catalyst Inhibitor Hint: Vinegar is inside the jar.

PQP: Write the formulas and symbols needed to create the skeleton equation for this reaction: Carbon tetrahydride gas (methane) reacts with oxygen gas to produce carbon dioxide gas and dihydrogen monoxide liquid.