AP Chemistry / Unit 4: Chemical Reactions
4.1 Introduction to Reactions
Notes
Evidence of a chemical reaction: gas forms, a precipitate forms, color changes, or temperature changes. Balanced equations conserve atoms.
Practice
Balance: $\_\,H_2+\_\,O_2\to\_\,H_2O$
4 H and 2 O on each side.
Which is evidence of a chemical change?
New substances form.
A balanced equation conserves:
Mass is conserved.
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