week 3

elementary step

Elementary processes are written to show how a chemical reaction progresses leading to an overall reaction. Such a collection is called a reaction mechanism. In a mechanism, elementary steps proceed at various speeds. The slowest step is the rate-determining step.

2nd-order

Identical Reactants. Two of the same reactant (A) combine in a single elementary step. where k is a second order rate constant with units of M -1 min -1 or M -1 s -1. Therefore, doubling the concentration of reactant A will quadruple the rate of the reaction.

Concentration

In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration.

EMP Pathway

The Embden-Meyerhof-Parnas (EMP) pathway allows the metabolic use of glucose to generate ATP, NADH, and several biosynthetic precursors such as 3-phosphoglycerate or pyruvate.

Surface Area

The surface area of a solid object is a measure of the total area that the surface of the object occupies

Zero Order Reaction

a coefficient of proportionality relating the rate of a chemical reaction at a given temperature to the concentration of reactant (in a unimolecular reaction) or to the product of the concentrations of reactants.

solvent

able to dissolve other substances.

unimolecular

consisting of or involving a single molecule.

termolecular

consisting of or involving three molecules; rare

bimolecular

consisting of or involving two molecules.

1st-order

depends on the concentration of only one reactant (a unimolecular reaction). Other reactants can be present, but each will be zero order. The rate law for a reaction that is first order with respect to a reactant A is. k is the first order rate constant, which has units of 1/s or s−1.

Frequency Factor

part of the Arrhenius equation, which was formulated by the Swedish chemist Svante Arrhenius in 1889. The pre-exponential factor is also known as the frequency factor, and represents the frequency of collisions between reactant molecules.

Rate Law

rate law equation must be determined experimentally for a given reaction at a given temperature. The rate is usually measured as a function of the initial concentrations of the reactants

Energy Profile

theoretical representation of a single energetic pathway, along the reaction coordinate, as the reactants are transformed into products.

rate limiting step

The rate determining step is the slowest step of a chemical reaction that determines the speed (rate) at which the overall reaction proceeds

intermediate

A reaction intermediate or an intermediate is a molecular entity that is formed from the reactants (or preceding intermediates) and reacts further to give the directly observed products of a chemical reaction. Most chemical reactions are stepwise, that is they take more than one elementary step to complete.

stoichiometry

Stoichiometry is the calculation of reactants and products in chemical reactions. Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equals the total mass

Temperature

Temperature is a measure of the hotness or coldness of the environment. If you add heat to water, like when you boil water to make spaghetti, the temperature of the water will rise. Temperature measures how much the molecules of a substance are moving.

gas constant

The gas constant is also known as the molar, universal, or ideal gas constant, denoted by the symbol R or R and is equivalent to the Boltzmann constant, but expressed in units of energy per temperature

frequency constant

The pre-exponential factor is also known as the frequency factor, and represents the frequency of collisions between reactant molecules.