Warm Up Write the name for these compounds: (NH 4 )F AgO 2. Write the chemical formula for these compounds: Magnesium bromide Copper (III) chloride Agenda -Notes Unit 5-1 -Demo Gummi Bear -WS Test Review Homework Online HW tonight Nov 3 - Test and Notebook

Unit 5-1 Chemical Reactions

Chemical Reactions  When one or more substance changes into different substances.  Always involve change of energy

Evidence of Chemical Reactions 1. change in temperature (exothermic or endothermic) 2. Precipitate (forming a insoluble solid) 3. Change in color 4. Produce gas

Evidence of Chemical Reactions 5. Release energy as light 6. Produce Sound 7. Change in odor 8. Absorption or release of electrical energy

Writing Chemical Equations  The arrow is read as “yields” or “produces” Coefficients Subscripts

Examples of chemical equations

Do not place bleach and ammonia next to each other

Writing Chemical Equations  Equations can be written with words or with formula (symbols) -Word Form: Sodium combine with chlorine gas produces sodium chloride -Chemical Formula: 2Na (s) + Cl 2 (g) → 2NaCl (s)

Check-In  Write the chemical equation of this statement. Iron reacts with oxygen in the air to produce rust (iron (III) oxide)

Other Information in Equations  (s) means solid  (l) means liquid  (g) means gas  (aq) means aqueous (dissolved in water)-also called a “solution”  ∆ (above the arrow) means heat is added  ⇌ represents that the reaction can happen in both directions

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