Reaction Rate
Reaction Rate - Related Videos
02:53
Reaction Rate
0 Views •
2020
The rate of reaction is the change in the amount of a reactant or product per unit time. Reaction rates are therefore determined by measuring the time dependence of some property that can be related to reactant or product amounts. Rates of reactions that consume or produce gaseous substances, for example, are conveniently determined by measuring changes in volume or pressure. The mathematical representation of the change in the concentration of reactants and products, over time, is the rate...
03:09
Measuring Reaction Rates
0 Views •
2020
Polarimetry finds application in chemical kinetics to measure the concentration and reaction kinetics of optically active substances during a chemical reaction. Optically active substances have the capability of rotating the plane of polarization of linearly polarized light passing through them—a feature called optical rotation. Optical activity is attributed to the molecular structure of substances. Normal monochromatic light is unpolarized and possesses oscillations of the electrical field in...
10:49
Determining Rate Laws and the Order of Reaction
0 Views •
2023
Source: Laboratory of Dr. Neal Abrams — SUNY College of Environmental Science and Forestry All chemical reactions have a specific rate defining the progress of reactants going to products. This rate can be influenced by temperature, concentration, and the physical properties of the reactants. The rate also includes the intermediates and transition states that are formed but are neither the reactant nor the product. The rate law defines the role of each reactant in a reaction and can be used to...
02:55
Temperature Dependence on Reaction Rate
0 Views •
2020
The Collision Theory Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates. The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
02:33
Rate Law and Reaction Order
0 Views •
2025
The rate of a reaction is affected by the concentrations of reactants. Rate laws (differential rate laws) or rate equations are mathematical expressions describing the relationship between the rate of a chemical reaction and the concentration of its reactants. For example, in a generic reaction aA + bB ⟶ products, where a and b are stoichiometric coefficients, the rate law can be written as: rate = k[A]m[B]n [A] and [B] represent the molar concentrations of reactants, and k is the rate...
FAQs
A collision does not automatically convert reactants into products. Particles must meet with a suitable orientation and sufficient energy to overcome the activation energy, the energy barrier associated with the chemical change. Collisions that fail either condition do not contribute to product formation, so the frequency of successful collisions helps determine how rapidly the reaction proceeds.
These conditions influence how often reactant particles undergo effective collisions. Increasing concentration can change the frequency of encounters between particles, while temperature affects the energetic conditions of those encounters. Increasing surface area exposes more reactant material for interaction. Because each factor changes collision opportunities or effectiveness, the observed rate can change when reaction conditions are adjusted.
A catalyst provides a way to alter the reaction rate without being identified as a reactant converted into the final products. Its significance comes from changing how the chemical process proceeds, including the conditions associated with overcoming the activation energy. In practice, catalysts help chemists control product formation and design reactions that are more efficient or safer.
Measurement focuses on how quickly reactants are converted into products under defined conditions. A researcher can compare product formation or reactant consumption over time, while controlling variables such as concentration, temperature, surface area, and the presence of a catalyst. The resulting rate data show how changes in conditions affect the progress of the chemical reaction.
Measured rates provide evidence for how a reaction responds to changes in its conditions. Chemists use these relationships to establish rate laws, which describe the dependence of rate on relevant variables, and to investigate reaction mechanisms, the processes by which reactants become products. Together, these analyses support predictions about how altered conditions will affect product formation.
Understanding rate helps control chemical change in industrial synthesis, environmental chemistry, and biochemical processes. It can guide the selection of conditions that influence product formation, support predictions about how a system responds to change, and contribute to safer, more efficient reaction design. The same principles therefore connect laboratory measurements with practical chemical and biological systems.