Parallel or Competitive Reactions
When a substance reacts simultaneously to give two different products, a parallel or competitive reaction is said to take place.
- Two first order reactions:
and, with constants and and rate equations, and
The integrated rate equations are then ; and .
One important relationship in this case is
- One first order and one second order reaction:
This can be the case when studying a bimolecular reaction and a simultaneous hydrolysis (which can be treated as pseudo order one) takes place: the hydrolysis complicates the study of the reaction kinetics, because some reactant is being "spent" in a parallel reaction. For example A reacts with R to give our product C, but meanwhile the hydrolysis reaction takes away an amount of A to give B, a byproduct: and . The rate equations are: and . Where is the pseudo first order constant.
The integrated rate equation for the main product is, which is equivalent to . Concentration of B is related to that of C through
The integrated equations were analytically obtained but during the process it was assumed that therefeore, previous equation for can only be used for low concentrations of compared to 0
Read more about this topic: Rate Equation
Famous quotes containing the words parallel, competitive and/or reactions:
“The universe expects every man to do his duty in his parallel of latitude.”
—Henry David Thoreau (1817–1862)
“Developing the muscles of the soul demands no competitive spirit, no killer instinct, although it may erect pain barriers that the spiritual athlete must crash through.”
—Germaine Greer (b. 1939)
“We have all had the experience of finding that our reactions and perhaps even our deeds have denied beliefs we thought were ours.”
—James Baldwin (1924–1987)