reactions. reaction types single-replacement one element replaces a second element in a compound ...
TRANSCRIPT
REACTIONS
Reaction Types
Single-replacement One element replaces a second element in
a compound
Cl2 + 2 NaBr 2 NaCl + Br2
Zn + H2SO4 ZnSO4 + H2
Refer to Table 11.2 on page 333
Reaction Types (cont)
Decomposition Single compound breaks down into 2 or
more simpler compounds
2 H2O 2 H2 + O2
CaCO3 CaO + CO2
Reaction Types (cont)
Combination 2 or more reactants form a single new
substance
Fe + S FeS
2CaO + 2 H2O 2 Ca(OH)2
Practice
Complete the worksheet in groups.
Have the first 5 equations completed by the end of class.
Reaction Types (cont)
Double-replacement Positive ions are exchanged between two
compounds Generally occur in aqueous solution and
produce a precipitate
AgNO3 + NaCl AgCl + NaNO3
2 NaOH + H2SO4 Na2SO4 + 2 H2O
Reaction Types (cont)
Combustion Element, or compound, reacts with oxygen,
producing heat Oxygen always involved as reactant
CH4 + 2 O2 CO2 + 2 H2O
C2H5OH + 3 O2 2 CO2 + 3 H2O
BALANCING CHEMICAL EQUATIONS
Example Bike Manufacturing
Frame + wheel + handlebar + pedal = bicycle Identify the components, how many are
needed? 1 frame, 2 wheels, 1 handlebar and 2 pedals
Skeleton equation: F + W + H + P = FW2HP2
Balanced? F + 2 W + H + 2 P = FW2HP2
http://youtu.be/QjVYz00-Kxc
Example
Equation IS balanced:
Process
Write the skeleton equation first Use coefficients to balance the equation
Law of Conservation of Mass Mass is conserved Atoms in products are the same as the
reactants, but rearranged
Practice
Zn + HCl ZnCl2 + H2
Zn + 2 HCl ZnCl2 + H2
C2H6 + O2 CO2 + H2O 2 C2H6 + 7 O2 4 CO2 + 6 H2O
BCE Practice
___ Al2O3 ___ Al + ___ O2
___ BaCl + ___ H2SO4 ___ BaSO + ___ HCl
___ CuCl2 + H2S ___ CuS + ___ HCl
Questions?
Summary
What is a coefficient? What are the on the left of the
chemical equation? On the right? Worksheet due tomorrow!!