Intro. to CHEMICAL REACTIONS Notes
Binder organization
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Tab 1: Reference Sheets
Tab 2: Chemistry Handouts
Tab 3: Math Handouts
Tab 4: HW, Tests, quizzes
Tab 5: Projects
Physical vs. Chemical Change
• Physical change: A substance changes
appearance, but it is still that substance
– Example: Tearing paper
• Chemical change: A substance actually
changes into something else
– Example: Burning paper
Chemical Reactions
• Chemical reaction: The process by which one or
more substances change to form one or more
different substances
• Evidence of Chemical Reactions
1. Color change
2. Bubbles (gas formed)
3. Turns cloudy (solid/precipitate formed)
4. Temperature change
5. Change in smell
Chemical Reactions
• Chemical reaction: The process by which one or
more substances change to form one or more
different substances
• Evidence of Chemical Reactions
1. Color change
2. Bubbles (gas formed)
3. Turns cloudy (solid/precipitate formed)
4. Temperature change
5. Change in smell
Chemical Reactions
• Chemical reaction: The process by which one or
more substances change to form one or more
different substances
• Evidence of Chemical Reactions
1. Color change
2. Bubbles (gas formed)
3. Turns cloudy (solid/precipitate formed)
4. Temperature change
5. Change in smell
Chemical Reactions
• Chemical reaction: The process by which one or
more substances change to form one or more
different substances
• Evidence of Chemical Reactions
1. Color change
2. Bubbles (gas formed)
3. Turns cloudy (solid/precipitate formed)
4. Temperature change
5. Change in smell
Is it a chemical or physical change?
• Sugar dissolving in
tea
Is it a chemical or physical change?
• Logs burning
Is it a chemical or physical change?
• Breaking water up by
separating it into
hydrogen and oxygen
• 2H2O  2H2 + O2
Is it a chemical or physical change?
• Cutting paper
Is it a chemical or physical change?
• Crushing an aspirin
Is it a chemical or physical change?
• Metal rusting
Is it a chemical or physical change?
• An egg rotting
Is it a chemical or physical change?
• An egg breaking
Writing Chemical Equations
Mg (s) + O2 (g)  MgO (s)
Reactants
• Reactants = starting materials
• Products = ending materials
Product
States of Matter:
Solid = (s)
Liquid = (l)
Gas = (g)
Aqueous = (aq)
dissolved in water
Writing Chemical Equations
• Example:
– Hydrogen gas reacts with oxygen gas to
produce liquid water
H2 (g) + O2 (g)  H2O (l)
“reacts with”
“combines with”
“is added to”
“to produce”
“yields”
“to make”
“synthesizes”
Write the Chemical Equation for the following:
• Solid carbon reacts with oxygen gas to
produce gaseous carbon dioxide
C(s) + O2(g)  CO2(g)
Write the Chemical Equation for the following:
• Solid zinc metal is added to an aqueous
solution of hydrochloric acid (HCl) to produce
hydrogen gas and aqueous zinc (II) chloride.
Zn(s) + HCl(aq)  H2(g) + ZnCl2(aq)