Nucleophilic Substitution SN1-SN2

The objective of this laboratory experiment is to study both SN1 and SN2 reactions. The first part of the lab focuses on synthesizing 1-bromobutane from 1-butanol by using an SN2 mechanism. The obtained product will then be analyzed using infrared spectroscopy and refractive index. The second part of the lab concentrates on how different factors influence the rate of SN1 reactions. The factors that will be examined are the leaving group, Br – versus Cl-; the structure of the alkyl group, 3◦ versus 2◦; and the polarity of the solvent, 40 percent 2-propanol versus 60 percent 2-propanol.

The Diels-Alder reaction was discovered and named after the Nobel Prize winning scientists Kurt Alder and Otto Diels in 1928. Such a reaction occurs when a diene with two adjacent double bonds is mixed with a dienophile consisting of a double bond in order to create a cyclohexene. The diene must be in the s-cis conformation in order for the electron transfer to engage correctly. If the diene in question is in s-trans conformation then the access to the molecules is limited, thus, no reaction can occur. The dienophile we used was maleic anhydride. Maleic anhydride possesses high electron withdrawing characteristics which caused a very quick reaction. The reaction will

In this lab experiment we determined the kinetic rate constant for a solvoysis reaction and observed how a change in polarity of the solvents affects the reaction rate. For the specific reaction that we did in the lab we actually measured the formation of HCl since the rate of

The purposes of this experiment were to model a bimolecular nucleophilic substitution reaction between potassium hydroxide (KOH) with 1-bromopropane and determine whether it follows a second-order rate law mechanism. A rate constant of 0.0684 M-1 min-1 was obtained for this reaction at 45.1°C, which was determined through equilibrating the reaction and performing titrations of 0.390 M KOH with 0.1000 M hydrochloric acid (HCl). The activation energy calculated from class data was 50.188 kJ/mol, which deviated largely from the literature range value of 72.80–83.76 kJ/mol. It was concluded that the reaction was consistent with the predicted SN2 mechanism, based on the regression of a trendline.

Ans. Dipole moments of Fluoro-Cyclohexane have increased by a factor of 611.6 as compared to cyclohexane.

(b) Calculate the initial rate of absorption ofC12H26Sfrom a 1 mM solution at 20 °C ifits initial sticking coefficient is 1×10–6.6.A gas phase reaction between atomA and a diatomic molecule BC has a positive activationenergy to reach a collinear transition state. Describe how the reaction to form AB occurs.Suggest a plausible explanation for why the product AC is not formed.7.Calculate thecollision rateof waterwith a surface ifthe surfaceis exposed to (a) water vaporwith a pressure of 1 atm and (b) liquid water?The system is held at 350 K.8.The forward and reverse rate constants have been measured for the gas-phase reactionH2(g) +I2(g)2HI(g).The reaction is bimolecular in both directions with Arrhenius parametersA=4.45×105dm3mol–1s–1,Ea=170.3kJ mol–1(forward reaction)A'=5.79×101dm3mol–1s–1,Ea' =117.6kJ mol–1(reverse reaction)Computek,k' (rate constant for the reverse reaction),K,ΔrG°,ΔrH°, andΔrS° at

In a bimolecular nucleophilic substitution or SN2 reaction, there is only one-step. This occurs because the addition of the nucleophile and the elimination of the leaving group spontaneously occur at the same time.

OMRI is based on the Overhauser effect that enhances the amplitude of the NMR signal of the solvent water protons while the ESR transition of the dissolved paramagnetic solute is saturated [9,19-22]. The enhancement of the proton polarization, of the NMR signal of the 1H nuclei (I = 1/2) of water molecules with couplings to an unpaired electron spin S = 1/2 of a dissolved free radical [43,44], is defined as:

Objective: The objective of this lab is to observe the synthesis of 1-bromobutane in an SN2 reaction, to see how a primary alky halide reacts with an alcohol.

The amount measured are merely estimates, as there are always uncertainty of 0.2 mL, which is a significant amount when dealing with small amounts of solution. Next, the rate constant at 40°C would be 5.0152 s-1 by using the equation found in the graph of ln absorbance versus time: y=3.2527(1/40) + 4.933 = 5.0152 s-1. Nevertheless, to the study the rate of the chemical reaction and how it is affected by concentration of the reactants, the rate constant, and activation energy is important. According to the chemist, Kim Davis, increasing the temperature increases the rate of the reaction because by increasing the temperature of a system the average kinetic energy of its constituent particles are increasing. As the average kinetic energy increases, the particles move faster, collide more frequently, possessing greater energy when they collide, therefore increasing the rate of the reaction. Moreover, concentration increases the rate of the reaction because the more reactant particles that collide per unit of time, the more often a reaction can occur. As a result, this experiment fostered knowledge on the relationships between the variables of the rate

The overall aim of this experimental investigation is to further research and investigate the factors of temperature and concentration and how these two elements can alter or change the speed or rate of a reaction. The aim will be investigated thoroughly, with multiple experiments being conducted to ultimately fulfil this aim, with as much detail and data as possible so an in-depth conclusion can be delivered.

In reference to the collision theory, molecules act as small spheres that collide and bounce off each other, transferring energy among themselves when the collide. In order for a reaction to occur, there must be collisions between molecules. Through experimentation, factors are discovered that influence the reaction rates of chemical reactions include the concentration of reactants, temperature, surface area, the physical state of reactants, and a catalyst. This experiment regarding the factors that affect reaction rate tests the effects of increased concentration and

As mentioned above, the initial addition (CHClBr+NO2→ CHClBrNO2 a) is barrierless and extremely exothermic. Considering the lower energy barriers for subsequent reactions, a, once formed, will isomerize or dissociate to the products. The energy information in the initial addition process is critically important for such case in the kinetic calculations. However, IRC calculation can not be conducted for the barrierless reaction. Since the electronic interaction between C in CHClBr and N in NO2 plays a significant role in this process, the energy profile of the association can be obtained by the relaxed scan, in which the C-N distance in a is fixed from r=2.2 to 3.6 Å in a step size of 1.0 Å and remaining geometries are optimized at B3LYP/6-31+G(d) level using tight convergence criteria. Subsequently, CASPT2 method is utilized to calculate the single point energies. Here, the energy of the reactants at r=10 Å are set to be zero for CASPT2 method. In order to account for the dynamic electron correlation, the CASPT2(16,11)/aug-cc-pVTZ energies are scaled by a factor of 1.18, corresponding to the ratio of the dissociation energies of a calculated at CCSD(T)/6-311++G(d,p) level (-45.17 kcal/mol) and the CASPT2(16,11)/aug-cc-pVTZ level (38.29 kcal/mol). Both of the results with ZPE correction are shown in Figure 3. Figure 3 confirmed our assumption that a is formed barrierlessly via carbon-to-nitrogen approach. Based on the energy information

The percentage removal of fluoride ion and amount adsorbed (in mg/g) were calculated using the following equations.

The approach described above is novel and original because we are integrating the high level of programmability of DNA with natural catalysts, which are very significant to progress in many different scientific fields. Such integration enables coupling of enzymes to circuits that are capable of decision making and self-regulation, leading to an unprecedented level of control of catalytic reactions. To achieve our objectives, we will develop methods to systematically design, model and test both dynamic and structural components. We will also create software and mathematical tools that can predict the dynamic behavior of individual catalytic modules and multi-modular circuits.