Chemical formulae and Rates of reaction Flashcards
State symbols
(s) - solid
(l) - liquid
(g) - gas
(aq) - aqueous (dissolved in water)
e.g
2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g)
Word equations
Copper + Oxygen → Copper oxide
[Reactants] [Product]
Symbol equations
Cu + O2 → CuO
Balanced symbol equations
2Cu + O2 → 2CuO
Factors affecting rate of reaction
-explain using particle theory
- Surface Area
- smaller solid particles (more SA) increases rate of reaction
- particles around it will have more area to work on, therefore more collisions - Concentration
- increasing concentration increases the rate of reaction
- if a solution more concentrated there will be more particles of reactants in the same volume of solvent
- makes collision of particles more likely - Temperature
- when temp is increased particles move faster, so more collisions
- faster movement means more energy so more collisions will have enough energy for reaction to happen - Catalyst
- increase rate of reaction without being changed/used up
- works by providing an alternative pathway with lower activation energy
Collision theory
Rate of reaction depends on how often and how hard particles collide into each other
Activation Energy
-represent on a reaction profile
The minimum amount of energy particles need to collide successfully and produce a reaction
(check iPad )
Marble chips and hydrochloric acid
- decrease/increase SA of marble chip: slower/faster rate of reaction
- half/increase concentration of acid`: slower/faster
- increase/decrease temp
Decomposition of hydrogen peroxide
- addition of magnesium oxide: faster rate of reaction, oxygen produced
- no magnesium oxide: slower, no oxygen produced
How does a catalyst speed up a reaction?
By providing an alternative pathway with lower activation energy
