Evidence for Chemical Reactions 1.Name 3 of the 5 evidences. 2.Name for OF 2 3.Formula for Tin II Sulfide

What is the difference between a chemical change and a physical change? Physical –Alters ________ –Alters __________ –Does not make _______________ Examples: Chemical –Bonds ______ and new bonds _______ –______________ formed Examples:

Chemical or Physical Change?

What five pieces of evidence indicate a chemical change?

What are some observations made in the discovery?

Demonstrations: What evidence of a chemical reaction is occuring? Barium hydroxide + ammonium nitrate

Demonstrations: What evidence of a chemical reaction is occuring? Silver nitrate + sodium chloride

Demonstrations: What evidence of a chemical reaction is occuring?

What information does a chemical equation contain? Reactants ____ Products Reactants ____________ Products Reactants ____ Products The _________ separates the reactants on the left from the products on the right of the equation. The __________ separates the individual reactants and individual products on each side of the equation.

Examples Iron + Oxygen → Iron (III) oxide Hydrogen peroxide → Water + oxygen Methane + oxygen → Carbon dioxide + water

What does the principle of conservation of mass state? Matter is not created or destroyed, only _____________. All ___________ at the start of a reaction are present at the end. Remember, in a chemical reaction, _________ are not created or destroyed; they are simply prearranged / deranged / rearranged / homeontherange.