1.1-1.8 Flashcards
Homogenous reaction def
-Reactants are in the same phase (aq), (g), or (l), thoroughly mixed
-Faster than hetero. reactions
-eg Ag+(aq) + Cl-(aq) -> AgCl(s)
Heterogenous reaction def
Reactants are in the 2 or more phases, not thoroughly mixed (2 solids cant mix)
-Slower than homo. reactions
-eg, 2Al(s) + 3I2(s) -> 2AlI3(s)
Which 5 factors can increase rate of a homogenous reaction
- Increasing temp
- Increasing reactant concentration
- Adding catalyst
- Changing nature of reaction
- Increasing pressure of gases
Which 7 factors can increase rate of a hetero. reaction (UNSURE)
- Increasing temp
- Increasing reactant concentration
- Adding catalyst
- Changing nature of reaction
- Increasing pressure of gases
- Increasing surface area of a solid
- Agitation
Collision theory def
Reaction rates depend on collisions between reactant particles
A reaction with less bonds to break and/or form will have a slower or faster rate of reaction?
Faster
A reaction with weaker bonds to break will have a slower or faster rate of reaction?
Faster
Catalyst def
-Chemical added to a reaction that increases rate, recovered at end of reaction
-lowers reaction time
-lowers activation energy, wont change enthalpy
-must increase rate of slowest step to be effective
-appears on reactant side, then product side
Inhibitor def
Chemical that reduces rate if reaction by combining with a catalyst or reactant and prevents reaction from happening
Which factor will only increase a gaseous reaction rate
Pressure
Simple ionic reactions are faster or slower than more complex reactions
Faster
What happens when bonds are broken
-Energy must be added (thats equal to bond energy)
-PE increases
Enthalpy def.
-Total PE & KE of reaction, “heat of reaction”
-Symbol is H
Exothermic reaction def
-lose enthalpy, produces energy
-surroundings warmer
- -H, unless reverse
-kJ is in product side
-top left to bottom right on a graph
Endothermic def
-gain enthalpy, absorbs energy
-surroundings cooler
- +H, unless reverse
-kJ is on reactant side
-bottom left to top right on graph
If you increase the temperature of energy
-Increase average kinetic energy
-Increase amount of molecules with min. kinetic energy required to react
-Time required for reaction decreases
Every ___°C increase = double rate of reaction (for slow reactions)
10°C
Ineffective collisions def
-If reactants dont collide with enough activation energy, reactants wont react
- Ke is less than PE equal to Ea
Effective collisions def
If reactants collide with enough “activation energy”, reactants react to make products
-KE more than Ea needed
-Need enough KE (converts to PE)
-Needs correct alignment
Activation energy def
-Min./difference energy needed to change reactants into an activated complex/successful collision
Rank the phases fastest to slowest
Aq, g, l, s
What phase does concentration specifically affect
Aq/solution
What phase does surface area specifically affect
Solid
