intro to reactions (p. 241 – 250)
DESCRIPTION
Ch. 8 – Chemical Reactions. Intro to Reactions (p. 241 – 250). A.Signs of a Chemical Reaction. Evolution of ________ and ________ Formation of a _______ Formation of a ___________ _________ change. B.Law of Conservation of Mass. mass is neither created nor destroyed in a chemical reaction. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/1.jpg)
I II III IV VC. Johannesson
I. Intro to Reactions
(p. 241 – 250)
Ch. 8 – Chemical Reactions
![Page 2: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/2.jpg)
C. Johannesson
A.Signs of a Chemical Reaction
Evolution of ________ and ________
Formation of a _______
Formation of a ___________
_________ change
![Page 3: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/3.jpg)
C. Johannesson
B.Law of Conservation of Mass mass is neither created nor destroyed
in a chemical reaction
4 H
2 O
4 H
2 O4 g 32 g
36 g
total mass stays the same atoms can only rearrange
![Page 4: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/4.jpg)
C. Johannesson
C. Chemical Equations
A+B C+DREACTANTS PRODUCTS
![Page 5: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/5.jpg)
C. Johannesson
p. 246
C. Chemical Equations
![Page 6: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/6.jpg)
C. Johannesson
D. Writing Equations
Identify the substances involved. Use symbols to show:
2H2(g) + O2(g) 2H2O(g)
How many? - coefficient
Of what? - chemical formula
In what state? - physical state Remember the diatomic elements.
![Page 7: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/7.jpg)
D. Writing Equations
Two atoms of aluminum react with three units of aqueous copper(II) chloride to produce three atoms of copper and two units of aqueous aluminum chloride.
• How many?• Of what?• In what state?
![Page 8: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/8.jpg)
C. Johannesson
E. Describing Equations
Describing Coefficients:
individual atom = “atom”
covalent substance = “molecule”
ionic substance = “unit”
3 molecules of carbon dioxide
2 atoms of magnesium
4 units of magnesium oxide
3CO2
2Mg
4MgO
![Page 9: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/9.jpg)
E. Describing Equations
• How many?• Of what?• In what state?
Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g)
![Page 10: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/10.jpg)
I II III IV VC. Johannesson
II. Balancing Equations
(p. 250-254)
Ch. 8 – Chemical Reactions
![Page 11: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/11.jpg)
C. Johannesson
A. Balancing Steps
1. _________ the unbalanced equation.
2. _________ atoms on each side.
3. _____ coefficients to make #s equal.
Coefficient subscript = # of atoms
4. _________ coefficients to lowest possible ratio, if necessary.
5. Double check atom __________!!!
![Page 12: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/12.jpg)
C. Johannesson
B. Helpful Tips
Balance one element at a time. Update ALL atom counts after adding
a coefficient. If an element appears more than
once per side, balance it last. Balance polyatomic ions as single
units. “1 SO4” instead of “1 S” and “4 O”
![Page 13: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/13.jpg)
Al + CuCl2 Cu + AlCl3
Al
Cu
Cl
C. Balancing Example
Aluminum and copper(II) chloride react to form copper and aluminum chloride.
![Page 14: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/14.jpg)
I II III IV VC. Johannesson
Ch. 8 – Chemical Reactions
III. Types of Chemical Reactions
(p. 256 - 267)
![Page 15: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/15.jpg)
C. Johannesson
A. Combustion
CH4(g) + 2O2(g) CO2(g) + 2H2O(g)
the burning of any substance in O2 to produce heat
A + O2 BCH4(g) + 2O2(g) CO2(g) + 2H2O(g)
![Page 16: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/16.jpg)
C. Johannesson
Na(s)+ O2(g)
C3H8(g)+ O2(g)
A. Combustion
Products: contain oxygen hydrocarbons form CO2 + H2O
CO2(g) + H2O(g)
Na2O(s) 4 2
![Page 17: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/17.jpg)
C. Johannesson
B. _____________
the combination of 2 or more substances to form a compound
only one product
A + B AB
![Page 18: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/18.jpg)
C. Johannesson
B. _____________
H2(g) + Cl2(g) 2 HCl(g)
![Page 19: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/19.jpg)
C. Johannesson
Al(s)+ Cl2(g) AlCl3(s)
B. _____________
Products: ionic - cancel charges covalent - hard to tell
![Page 20: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/20.jpg)
C. Johannesson
C. _______________
a compound breaks down into 2 or more simpler substances
only one reactant
AB A + B
![Page 21: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/21.jpg)
C. Johannesson
C. ________________
2 H2O(l) 2 H2(g) + O2(g)
![Page 22: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/22.jpg)
C. Johannesson
KBr(l) K(s) + Br2(l)
C. ________________
Products: binary - break into elements others - hard to tell
![Page 23: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/23.jpg)
23
The “Activity Series” of Metals Lithium Potassium Calcium Sodium Magnesium Aluminum Zinc Chromium Iron Nickel Lead HydrogenHydrogen Bismuth Copper Mercury Silver Platinum Gold
1) Metals can replace other metals, provided they are above the metal they are trying to replace (for example, zinc will replace lead)
2) Metals above hydrogen can replace hydrogen in acids.
3) Metals from sodium upward can replace hydrogen in water.
Higher activity
Lower activity
![Page 24: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/24.jpg)
24
The “Activity Series” of Halogens
Fluorine Chlorine Bromine Iodine
Halogens can replace other halogens in compounds, provided they are above the halogen they are trying to replace.
2NaCl(s) + F2(g) 2NaF(s) + Cl2(g)
MgCl2(s) + Br2(g) ???No Reaction!
???
Higher Activity
Lower Activity
![Page 25: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/25.jpg)
C. Johannesson
D. __________ ________________ one element replaces another in a
compound metal replaces metal (+) nonmetal replaces nonmetal (-)
A + BC B + AC
![Page 26: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/26.jpg)
C. Johannesson
D. __________ ________________
Cu(s) + 2AgNO3(aq) Cu(NO3)2(aq) + 2Ag(s)
![Page 27: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/27.jpg)
C. Johannesson
Fe(s)+ CuSO4(aq) Cu(s)+ FeSO4(aq)
D. __________ ________________
Products: metal metal (+) nonmetal nonmetal (-) free element must be more active (check activity series)
Br2(l)+ NaCl(aq) N.R.
![Page 28: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/28.jpg)
C. Johannesson
AB + CD AD + CB
E. __________ ________________ ions in two compounds “change partners” cation of one compound combines with
anion of the other
![Page 29: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/29.jpg)
C. Johannesson
E. __________ ________________
Pb(NO3)2(aq) + K2CrO4(aq) PbCrO4(s) + 2KNO3(aq)
![Page 30: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/30.jpg)
C. Johannesson
Pb(NO3)2(aq)+ KI(aq) PbI2(s)+ KNO3(aq)
E. __________ ________________ Products:
switch negative ions one product must be insoluble (check
solubility table)
NaNO3(aq)+ KI(aq) N.R.
2 2
![Page 31: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/31.jpg)
I II III IV VC. Johannesson
IV. Reaction Energy
(p. 514 - 517)
Ch. 17 – Chemical Reactions
![Page 32: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/32.jpg)
C. Johannesson
A. Reaction Pathway
Shows the change in energy during a chemical reaction
![Page 33: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/33.jpg)
C. Johannesson
B. _____________ Reaction
reaction thatreleases energy
products have lower PE than reactants
2H2(l) + O2(l) 2H2O(g) + energy
energyreleased
![Page 34: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/34.jpg)
C. Johannesson
C. _____________ Reaction
reaction that absorbs energy
reactants have lower PE than products
2Al2O3 + energy 4Al + 3O2
energyabsorbed
![Page 35: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/35.jpg)
I II III IV VC. Johannesson
V. Reaction Rate
(p. 532 - 541)
Ch. 17 – Chemical Reactions
![Page 36: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/36.jpg)
C. Johannesson
A. Collision Theory
Reaction rate depends on the collisions between reacting particles.
Successful collisions occur if the particles...
collide with each other
have the correct orientation
have enough kinetic energy to break bonds
![Page 37: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/37.jpg)
C. Johannesson
A. Collision Theory
Particle Orientation
Required Orientation
Successful CollisionUnsuccessful
Collisions
![Page 38: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/38.jpg)
C. Johannesson
A. Collision Theory
_____________ Energy (Ea)
minimum energy required for a reaction to occur
ActivationEnergy
![Page 39: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/39.jpg)
C. Johannesson
A. Collision Theory
Activation Energy depends on reactants low Ea = fast rxn rate
Ea
![Page 40: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/40.jpg)
C. Johannesson
B. Factors Affecting Rxn Rate
______________ __________ high SA = fast rxn rate more opportunities for collisions Increase surface area by…
-1.
-2.
![Page 41: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/41.jpg)
C. Johannesson
B. Factors Affecting Rxn Rate
_______________ high conc = fast rxn rate more opportunities for collisions
![Page 42: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/42.jpg)
C. Johannesson
B. Factors Affecting Rxn Rate _______________
high temp = fast rxn rate
high KE
- fast-moving particles
-more likely to reach activation energy
![Page 43: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/43.jpg)
C. Johannesson
B. Factors Affecting Rxn Rate
Temperature
Analogy: 2-car collision
5 mph “fender bender”
50 mph “high-speed crash”
![Page 44: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/44.jpg)
C. Johannesson
B. Factors Affecting Rxn Rate
_______________ substance that increases rxn rate
without being consumed in the rxn lowers the activation energy
![Page 45: Intro to Reactions (p. 241 – 250)](https://reader036.vdocuments.mx/reader036/viewer/2022081419/56813051550346895d95ffe6/html5/thumbnails/45.jpg)
C. Johannesson
B. Factors Affecting Rxn Rate
Enzyme Catalysis