Rate of reaction, reversible reactions and dynamic equilibrium GapFill

The speed of a reaction is called its rate of reaction. This can be calculated by dividing the amount of a reactant used, or the amount of a  catalystmixtureside-productsolutiongasproduct formed, by the time taken for the reaction to occur. The amount can be the volume, the  concentrationdensitymasssurface areapressurerelative formula mass or the number of moles. Graphs of amount against time are usually  disconnectedcurvedstraightS-shapedZ-shapedoscillating lines. A straight line which touches the curve at only one point is called  a rate linea gradienta constant linean asymptotea line of best fita tangent.

Multiple factors can affect the rate of a general reaction:

• the  massfizzinessconcentrationsurface areatransparencyvolume of the solution or the  opacityentropyvolatilitycolourpressureflammability of a gas
• the presence of  a catalystan oxidising agentoxygena flameanother reactantan acid
• the  hardnesssurface areaconductivityflammabilitymelting pointmass of any solid reactant
• the temperature

 CollisionActivationMoleCatalystReactionConcentration theory can be used to explain how factors affect reaction rate. Higher concentrations or pressures lead to more  energeticweakpre-determinedunsuccessfulconservativefrequent collisions, and increasing the temperature increases collision frequency and the  surface areaenergypressureconcentrationsizeefficiency of the collisions. A catalyst provides a different reaction pathway with a lower  energy changetemperaturesurface-area-to-volume ratiopressureactivation energyrate.

Reversible reactions are reactions in which the products can react to form the reactants. They are represented using a  «<»→←⇌. Reversible reactions that are exothermic in one direction are  neutraljust as exothermicstaticunfeasibleendothermiceven more exothermic in the other direction. When the rate of the forward reaction and the rate of the backward reaction are equal, the reaction is  fastslowingunstablestoppedat dynamic equilibriumcomplete.