Related Experiment Video
Updated: Feb 23, 2026
One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates
Published on: January 15, 2018
Kinetics and Mechanism of the Chlorate-Nitrous Acid Reaction
Rafaela T P Sant'Anna1, Roberto B Faria1
1Instituto de Química, Universidade Federal do Rio de Janeiro , Av. Athos da Silveira Ramos 149, CT, Bloco A, 21941-909 Rio de Janeiro, Brazil.
Abstract:
The chlorate-nitrous acid reaction was investigated in acid media, using a high concentration of reagents. It was followed via ultraviolet-visible light (UV-vis) spectroscopy and presented a complex behavior. The order of reagents, and the products formed by this reaction, are dependent on the concentration of reagents. For the high concentration set we used, the reaction has shown a first-order behavior for H+ and HNO2, and an order equal to 0.79 for chlorate. In this case, chlorine dioxide is formed. Moreover, chlorine dioxide starts to form only after all HNO2 has been consumed. This is the first time chlorine dioxide was observed to be formed by this reaction. Reduction of the concentration of reagents decreases the order of HNO2 to 0.91 and no chlorine dioxide is formed. An isosbestic point was found at 312 nm, which indicates a 1:1 ratio between nitrate ion and nitrous acid species. A model, with 14 independent species and 12 reactions is presented, which is able to simulate the experimental behavior for the low and high concentrations sets of reagents and it is a significant improvement in the understanding of the complex nitrogen and chlorine aqueous chemistry.
More Related Videos
Related Concept Videos
02:14SN2 Reaction: Kinetics
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
03:08Rate-Determining Steps
In a multistep reaction mechanism, one of the elementary steps progresses significantly slower than the others. This slowest step is called the rate-limiting step (or rate-determining step). A reaction cannot proceed faster than its slowest step, and hence, the rate-determining step limits the overall reaction rate.
The concept of rate-determining step can be understood from the analogy of a 4-lane freeway with a short-stretch of traffic-bottleneck caused due to...
01:371° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
02:31Multi-Step Reactions
02:34Nucleophilic Substitution Reactions
In 1896, the German chemist Paul Walden discovered that he could interconvert pure enantiomeric (+) and (-) malic acids through a series of reactions. This conversion suggested the involvement of optical inversion during the substitution reaction. Further, in 1930, Sir Christopher Ingold described for the first time two different forms of nucleophilic substitution reactions, which are known as SN1 (nucleophilic substitution unimolecular) and SN2 (nucleophilic substitution...
03:06Reaction Mechanisms
For instance, the decomposition of ozone appears to follow a mechanism with two steps: