Nucleophilic Substitution Lab Report

In order for nucleophilic substitution to take place, an electron pair donor (the nucleophile) and an electron pair acceptor (the electrophile) with a good leaving group must be present. In this experiment, Sn2 nucelophilic substitution occurred. In Sn2 nucelophilic substitution, the nucleophile performs a “backside attack” at the same time the leaving group “leaves”, resulting in an inversion of configuration of the electrophile to form

Many reactions that exist in nature involve a double displacement between ions and reactants with solvents. A bimolecular nucleophilic substitution, or SN2 reaction, involves a nucleophilic attack on a substrate and the departure of a leaving group. A nucleophile is a compound or ion that donates electrons to promote bond formation (Caldwell, 1984). In order for a leaving group in a compound to leave, it must possess the characteristics of a weak base and be able to occupy electrons. Several factors affect the rate and favorability of such reaction, such as (Bateman, 1940). In addition, the substrate that is attacked by the nucleophile is commonly an unhindered primary substrate to allow the reaction to occur quicker. An SN2 reaction follows the second-order rate law.

860 W. S. Hamama, A. E. E. Hassanien, M. G. El-Fedawy, and H. H. Zoorob Vol 54

Reaction 1 involved a primary alcohol (OH), weak leaving group in the starting material and a reaction with a strong nucleophile (sodium bromide) and a polar protic solvent (sulfuric acid). The reaction was carried out through reflux and the product had a relatively high yield (75%) (Scheme 1).

The purpose of this experiment is to examine the reactivities of various alkyl halides under both SN2 and SN1 reaction conditions. The alkyl halides will be examined based on the substrate types and solvent the reaction takes place in.

A unimolecular nucleophilic substitution or SN1 is a two-step reaction that occurs with a first order reaction. The rate-limiting step, which is the first step, forms a carbocation. This would be the slowest step in the mechanism. The addition of the nucleophile speeds up the reaction and stabilizes the carbocation. This reaction is more favorable with tertiary and sometimes secondary alkyl halides under strong basic or acidic conditions with secondary or tertiary alcohols. In this experiment, the t-butyl halide underwent an SN1 reaction. Nucleophiles do not necessarily effect the reaction because the nucleophile is considered zero order, (which makes it a first order reaction.) The ion that should have the strongest effect in an SN1 reaction is the bromide ion. The bromide ion should be stronger because it has a lower electronegativity than chloride as well as a smaller radius.

Lab Title: Synthesis, Decomposition, Single Displacement and Double Replacement Chemical Reactions Purpose: The objective of lab four was to use the website Late Nite Labs to determine types of chemical reactions. Combining and/or heating various compounds, observing the reactions and balancing equations for the chemicals involved, reveals the chemical reactions. Materials: A computer, Internet, calculator and access to Late Nite Labs.

Single replacement reaction is when a cation replaces another cation in a pair. The reactants in a single-replacement are made up of one element and one compound. The zinc takes the place of the hydrogen and forms a product known as zinc chloride and hydrogen, where the hydrogen is left on its own. The hydrochloric acid is clear and the zinc is a small metal clump. After the reaction, zinc was still reusable and it produced a gas. One can predict that single replacement will occur because there is one element on its own.

Purpose: The purpose of this lab is to be able to perform four different types of chemical reactions. With the information gained from these reactions, identify the products of the reactants with be identified and balanced equations for the reactions observed will be written. Procedure: Provided by Teacher.

The mixture was allowed to sit for a few minutes so that the two layers could fully separate. Once separated, the product, which was on the bottom layer due to being more dense than the water, was funneled out and washed with 10 mL of 5% aqueous NaHCO3 and mixed again, making sure to vent the funnel so that CO2 build up could be released. The organic layer was not cloudy, so it did not require any drying with Na2SO4. The dry product was obtained by adding a few chips of calcium carbonate and the percent yield was calculated. An IR spectrum and an NMR analysis were then taken of the sample to see if the alcohol had been converted to an alkyl

The products of the primary alcohol reaction, 1-butanol and HCl, are 1-chlorobutane and water; products of the secondary alcohol, 2-butanol and HCl are 2-chlorobutane and water; products of the tertiary alcohol, 2-methyl-2-propanol are 2-methyl-2-chloropropane and water.

In this experiment, double replacement reactions amongst six aqueous compounds were witnessed. (Find better place for this sentence->)The six known solutions were NaOH, K2SO4, Cu (NO3)2, Pb(NO3)2, Co(NO3)2, and BaCl2. Following this, deductive reasoning was used to determine the identity of two unknown solutions, based off of how they reacted with the six standard compounds. In order to set up the experiment, firstly each of the six compounds were poured onto six makeshift "wells " on a mirrored sheet, with each well containing two drops of a single compound.

In class, we tested the Wooly Worm experiment, by using eight different color yarns to represent our worms and our planter, which was represented by the color blue. We used chopsticks as our beak to represent birds (predatory). We had twenty seconds each student to see how many worms (predator) we can eat, with total tries of eight times. In the experiment, the Wooly Worm population was represented by a highly variable, color. As a predator, black, blue and red, worms were harder to catch, reason being worms camouflage in between the blue grass, given a greater survival chance of life.

has also been undertaken in a bid to generate more potent molecule/s than the parent compound 1. The chemical modifications has been carried out in different parts of the molecule such as: i) α-methylene part of γ-butyro double bond (from the literature survey the exocyclic double bond seems to be as an important functionality for the chemical modification for anticancer activity14, and ii) on hydroxyl group, and iii) acetyl group of the molecule (Fig.1). Figure 1: Active sites (shown in red) of isoxanthanol (1) and xanthanol (1a) In the initial stage hydroxyl group of compound 1 was chosen for chemical modification in order to get desired acyl, aryl, cinnamyl ester derivatives 2-10 (Scheme 1), the formation of acyl derivatives were confirmed

These factors can transform bad leaving groups into ideal weak bases. Through the basic knowledge of how nucleophilic substitution reactions are driven, S_N 2 and S_N 1 mechanisms are further understood. Second order mechanisms, S_N 2 reactions, follow certain criterion that differentiate it from other reactions. When S_N 2 reactions are assessed the nature of the leaving group is characterized by alkyl halides. Primary halides compared to secondary halides are reacted faster which is important when looking at certain reactions.