Kinetics and equilibrium

HideShow resource information
  • Created by: Sophie
  • Created on: 15-05-14 19:02
Preview of Kinetics and equilibrium

First 374 words of the document:

Factors increasing rate of reaction
- Increased concentration/ pressure: molecules are closer together so there are more collisions
- Increase SA of solids or immiscible liquids (dispersed through solution by shaking): increases SA in
contact with other reactant, so more collisions
- Temperature: more kinetic energy, so more molecules with activation energy (= energy barrier
separating products and reactants) and which collide more
- Catalysts: can form an intermediate which requires less energy/bring reactants together to make
reaction more likely/ reduce activation energy required- not entirely reusable as can become
contaminated or hard to recover from products or change state (e.g. Lumps to fine powder) (used in
catalytic converters in cars- gases pass through ceramic block with honeycomb structure in which
inside is lined with catalyst, and then exit through exhaust pipe)
Collision theory
- Molecules in gas are in rapid random motion colliding with each other (=kinetic theory)
- Assumptions made in ideal gas law:
- Gas pressure results from molecules hitting walls of container
- No loss of energy when molecules hit walls
- Molecules are so far apart that their individual volumes can be neglected
- Molecules dont attract each other
- Average kinetic energy is proportional to temperature on kelvin scale
- At high temperature and low pressure, gases behave more like ideal gas (they are moving so fast
that any attractions can be ignored, at low pressure they take up a negligible amount of space)
- Real gases deviate from this law as when they get close to becoming a liquid, molecules get nearer
to each other- they would not be able to become liquid if there were no intermolecular forces at all
How to measure rate of reaction
- Rate of formation of gas (measure in syringe/ placing experiment on scales throughout)
- Rate of loss of precipitate (when a cross on white paper becomes visible)
-Use pH meter to measure pH
-Measure electrical conductivity if ions are
Hydrogen peroxide
-Catalyst: manganese (IV) oxide (MnO2)
-2H2O2 2HO + O

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Maxwell-boltzmann distribution
Reaction profiles
Higher temperature
Some reversible reactions
- Hydration of CoCl2 or CuSO4
- Decomposition of ammonium chloride (forward
reaction occurs when heated, backwards when
cooled): NH4Cl(s) NH3(g) + HCl(g)
- 3Fe(s) + 4HO(g) Fe3O4(s) + 4H2(g) (when water is
used to sweep away hydrogen, forward reaction occurs.…read more


No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all resources »