Nature of Reactants

If the number of bonds broken and formed during a reaction is very large, then the reaction is generally slow. 

Reaction 111 is the slowest reaction, since the number of broken and formed bonds is very large. 

Reaction IV is faster than reaction II because there is no bond breakage or formation occuring. 

The rate of a reaction is directly proportional to the concentration of reactants the higher the concentration of reactants, the faster the reaction occurs. The greater the number of molecules in the reacting substances per unit volume, the greater the probability of effective collisions. 

---

From the coverage made thus far, it may be of interest to record in one place the different factors which influence the rate of chemical reactions. The rate of chemical reaction depends essentially on four factors. The nature of reactants and products is one. For example, certain physical properties of the reactants and products govern the rate. As a specific example in this context mention may be of oxidation of metals. The volume ratio of metallic oxide to metal may indicate that a given oxidation reaction will be fast when the oxide is porous, or slow when the oxide is nonporous, thus presenting a diffusion barrier to the metal or to oxygen. The other two factors are concentration and temperature effects, which are detailed in Sections. The fourth factor is the presence of catalysts. 

Particular attention is now given to the characterization of the supported species, and to the control of stability and recycling of the catalyst. The behavior of the supported catalyst under the reaction conditions (temperature, pressure, and nature of reactants and products) is certainly a less well-developed area, even though these data are valuable for the conception and development of a fully recyclable catalyst. Very few chemical engineering studies have been so far reported they will become crucial if the objective is the synthesis of an industrial catalyst. 

Use collision theory and transition state theory to explain how concentration, temperature, surface area, and the nature of reactants control the rate of a chemical reaction. 

Zeolite crystallization represents one of the most complex structural chemical problems in crystallization phenomena. Formation under conditions of high metastability leads to a dependence of the specific zeolite phase crystallizing on a large number of variables in addition to the classical ones of reactant composition, temperature, and pressure found under equilibrium phase conditions. These variables (e.g., pH, nature of reactant materials, agitation during reaction, time of reaction, etc.) have been enumerated by previous reviewers (1,2, 22). Crystallization of admixtures of several zeolite phases is common. Reactions involved in zeolite crystallization include polymerization-depolymerization, solution-precipitation, nucleation-crystallization, and complex phenomena encountered in aqueous colloidal dispersions. The large number of known and hypo-... 

Kinetics deals with the rate (how fast) that a chemical reaction proceeds with. The reaction rate can be determined by following the concentration of either the reactants or products. The rate is also dependent on the concentrations, temperature, catalysts, and nature of reactants and products. 

The Nature of Reactants. No less effect on z and e is exerted by the nature of the reacting atoms of the molecule. The values of z and e are distinctly different for hydrocarbons, amines, and alcohols (on the same or similar catalysts). This complies with the multiplet theory of catalysis, according to which in the three reactions the following atomic groups, in which the vertical bonds pass over to the horizontal, are in contact with the catalyst ... 

Product distribution data (Table V) obtained in the hydrocracking of coal, coal oil, anthracene and phenanthrene over a physically mixed NIS-H-zeolon catalyst indicated similarities and differences between the products of coal and coal oil on the one hand and anthracene and phenanthrene on the other hand. There were differences in the conversions which varied in the order coal> anthracene>phenanthrene coal oil. The yield of alkylbenzenes also varied in the order anthracene >phenanthrene>coal oil >coal under the conditions used. The alkylbenzenes and C -C hydrocarbon products from anthracene were similar to the products of phenanthrene. The most predominant component of alkylbenzenes was toluene and xylenes were produced in very small quantities. Methane was the most and butanes the least predominant components of the gaseous product. The products of coal and coal oil were also found to be similar. The most predominant components of alkylbenzenes and gaseous product were benzene and propane respectively. The data also indicated distinct differences between products of coal origin and pure aromatic hydrocarbons. The alkyl-benzene products of coal and coal oil contained more benzene and xylenes and less toluene, ethylbenzene and higher benzenes when compared to the products from anthracene and phenanthrene. The gaseous products of coal and coal oil contained more propane and butanes and less methane and ethane when compared to the products of anthracene and phenanthrene. The differences in the hydrocracked products were obviously due to the differences in the nature of reactants. Coal and coal oil contain hydroaromatic, naphthenic, heterocyclic and aliphatic structures, in addition to polynuclear aromatic structures. Hydrocracking under severe conditions yielded more BTX as shown in Table VI. The yields of BTX obtained from coal, coal oil, anthracene and phenanthrene were respectively 18.5, 25.5, 36.0, and 32.5 percent. Benzene was the most... 

Nature of reactants. Some compounds are more reactive than others. In general, reactions that take place between ions in aqueous solutions are rapid. Reactions between covalent molecules are much slower. 

To investigate the relationship between the rate and the nature of reactants. 

Figure 4.4 presents a graphical interpretation of the correlation ratios under discussion. The type (4.75) correlation expressions are useful for semiquantitative analysis of variations in a large number of kinetic para meters of different processes on changing the nature of reactants within the given homological series. 

In the same way, Maixner et al. (4) claimed that the most important parameters for the formation of coke are the reaction temperature and the nature of reactants.They studied the conversion of... 

Salt effects have been studied for a large number of electron-transfer reactions. The effect of extremely dilute salt solutions can in most cases be accounted for by the Debye-Hiickel formalism, whereas explanations for more concentrated solutions vary. Among these are the associative nature of reactants and counterions as well as specific kinetic effects such as cation bridges between redox pairs to facilitate electron transfer. 

Note that more sophisticated models have been proposed to take into account the nonspherical nature of reactant and products, the eventual distribution of charges on different centers within the molecule [55], the eventual coupling between the inner shell and solvent fluctuation modes, and other factors [56]. Yet the simplest model described here is sufficient for our purposes, since it includes most of the essential features of electron transfer reactions. 

At the beginning of our work devoted to new potential applications of 1-chloroalkyl chloroformates and 1-chlo-roalkyl carbonates, available literature data as well as our preliminary experiments indicated strong variations in the products distribution resulting from nucleophilic attacks. Scheme 69 gives some examples demonstrating that the types of obtained products strongly depend on the nature of reactant. 

Of the following variables that can affect the rate of a reaction, which is tested in this experiment temperature, catalyst, concentration, surface area, or nature of reactants Explain your answer. 

On which of the following properties does the rate constant of a reaction depend (a) reactant concentrations, (b) nature of reactants, (c) temperature... 

The following example shows how knowing the nature of reactants and products makes it possible to predict entropy changes. 

A listing of polymers utilized to form coordination polymers by route (b) appears in Table 1. Table 2 contains a listing of families of chelating compounds utilized to form coordination polymers by route (c). Polymers formed by routes (a) and (c) typically contain definable repeat units, whereas structures of polymers formed by route (b) vary depending on the conditions, including solvent, T, nature of reactants and concentration ratio of the two reactants the structure will vary within a given chain for such polymers. 

Polyatomic nature of reactants and coverage dependent adsorption mode... 

Nature of Reactants Substances vary greatly in their tendency to react depending on their bond strengths and stmctures. 

STEP 3 Staple along the fold. Label the tabs Nature of Reactants, Concentration, Surface Area, Temperature, and Presence of a Catalyst. 

Batteries are also classified according to their chemistry (their system), that is, the chemical nature of reactants. The above-mentioned battery with silver oxide as an oxidant at the positive electrode and metallic zinc as negative electrode is called silver-zinc battery. ... 

Many compounds cannot be directly synthesized from their elements. In some cases, the reaction proceeds too slowly, or side reactions produce substances other than the desired compound. In these cases, AH°f can be determined by an indirect approach, which is based on Hess s law of heat summation, or simply Hess s law, named after the Swiss chemist Germain Hess. Hess s law can be stated as follows When reactants are converted to products, the change in enthalpy is the same whether the reaction takes place in one step or in a series of steps. In other words, if we can break down the reaction of interest into a series of reactions for which can be measured, we can calculate A//°xn for the overall reaction. Hess s law is based on the fact that because // is a state function, AH depends only on the initial and final state (that is, only on the nature of reactants and products). The enthalpy change would be the same whether the overall reaction takes place in one step or many steps. 

---