Rates Of Reaction Of The Halogenoalkanes

1616 words - 6 pages

Rates of reaction of the halogenoalkanes

scientific knowledge and understanding:

Halogenoalkanes are classified as either primary, secondary or
tertiary. In primary halogenoalkanes the halogen atom is covalently
bonded to a carbon atom which is bonded to one other carbon, to two
other carbons in secondary and three others in tertiary.

Apparatus for a reflux

Increasing the size of the halogen atom in the halogenoalkane decreases
the bond strength, increasing the reactivity of the molecule, as the bond is
easier to break.

BOND

BOND ENTHALPY (kJ mol-1)

carbon-fluorine 467
carbon-chlorine 340
carbon-bromine 280
carbon-iodine 240

It can clearly be seen that the bond enthalpy (energy needed to break bond)
of the C-X bond decreases as we move down as we go from C-F to C-I.
Halogenoalkanes are volatile liquids. As they are organic, any reactions
they partake in are usually quite slow and therefore must be heated under
reflux. A reaction carried out under reflux is one in which a condenser is
positioned vertically in the neck of the reaction flask to prevent any of the solvent/reactant liquids from evaporating.

Halogenoalkanes do not mix with water, so must be dissolved in ethanol before
being treated with any aqueous solutions.

Nucleophilic substitution is a reaction in which an electron-donor atom in a
molecule is eliminated, and replaced by another which will form a stronger
covalent bond in the

concerned molecule.

Primary halogenoalkanes will undergo nucleophilic substitution with
the following mechanism (SN2):

Nu – Nucleophile X – Halogen atom

A nucleophile is an atom/molecule, which has a lone pair of electrons.
It bonds by ‘attacking’ an electron deficient carbon atom and donating
its free pair of electrons. A nucleophile will only displace a halogen
it if it forms a stronger bond with the carbon.

In this investigation I will be examining the rate of reaction of
chloroethane, bromoethane and iodoethane, by treating them with a
solution of silver nitrate in a mixture of ethanol and water, and
timing how long it takes for a silver halide precipitate to become
visible.

The faster the precipitate appears, the more reactive the
halogenoalkane.

Primary halogenoalkanes will be used, as they take longer to react
than secondary or tertiary halogenoalkanes, and I want to be able to
keep up with the rate of the experiment.

The main reaction in this experiment will be the nucleophilic
substitution occurring between the halogenoalkane and water in the
solvent.

R–Hal + H2O ROH + H+ + Hal-

The ethanol in the aqueous solution will dissolve the halogenoalkanes
so they are able to mix with water.

Bonds in the water molecules will then break giving OH and H ions.
The OH ions will behave as a nucleophile because they have a lone
pair of electrons, which when accepted by the carbon, will form a
stronger bond...

Find Another Essay On Rates of Reaction of the Halogenoalkanes

Rates Of reaction- The reaction between limestone and hydrochloric acid

873 words - 3 pages think this as all the particles of limestone will be roughly the same size, the particles have a larger surface area than cubed limestone, therefore it will react the quickest. If you were to use cubed limestone it wouldn't be fair as no cube will be exactly the same size. In conclusion to this experiment, 0.5M of acid was the best to use as it had the best measurable reaction time.EquipmentThe equipment we will be using during this experiment is

Chemistry Report: Experiment on Rates of Reaction

3605 words - 14 pages Rates of Reaction CaCO3 + 2HCl → CaCl2 + H2O + CO2 In this report I will be suggesting my predictions on what the rates of reaction will be and what the actual rates of reaction are. I will do this by collecting data from experiments and I will show this by putting data into a table. The main aim of my experiment is to find the rate of reaction over time taken and the rate of reaction when the concentration of hydrochloric acid increases or

Marble chip investigation - rates of reaction, studying the effects of change in concentration of the acid

1745 words - 7 pages 稡oss head clamp稵ub稴topwatchSafetyHydrochloric acid is very corrosive, so care will be taken when handling it. Safety goggles will be worn throughout the investigation as the reaction could fizz violently and cause eye damage if it was to spit.Variables稵emperature稢oncentration of acid稴urface area of marble chips稭ass of marble chips稸olume of acidKey VariableThe only variable that I will

Investigating Reaction Rates of Sodium Thiosulphate and Hydrochloric Acid

2235 words - 9 pages Investigating Reaction Rates of Sodium Thiosulphate and Hydrochloric Acid Aim: To investigate the rate of reaction of Sodium Thiosulphate and Hydrochloric acid. In this investigation I will be varying the concentration of Sodium Thiosulphate only and not the Hydrochloric acid concentration. In this investigation I will use the following word equation: Sodium Thiosulphate + Hydrochloric acid In this

Rates of Reaction - Sodium Thiosulphate and Hydrochloric acid

1973 words - 8 pages Rates of Reaction - Sodium Thiosulphate and Hydrochloric acid In this piece of coursework, I will study how concentration affects the rate of reaction. I will do so by timing the reaction of Sodium Thiosulphate with an acid. In this coursework, I will include background knowledge, prediction, safety, results, calculations, graphs, an analysis, conclusion and an evaluation. In my evaluation I will comment on how reliable my results were and how

Investigating how surface area affects rates of reaction

782 words - 3 pages Investigating how surface area affects rates of reaction.Background Info:Enzymes are biological catalysts. They break down the chemical they are uniquely made for, such as proteins, fats and some harmful substances like Hydrogen Peroxide.An enzyme basically works on a key and lock like system. The enzyme is unique to its self but many others may be close to the exact shape, but not quite. Therefore allowing substrates to fit into its activesite

The Speed of Reaction

984 words - 4 pages the air Camp stand – to hold the equipment Boson – it heats up the water Tripod – to hold the beaker at a certain height that has the most heat Ice – to cool down the water of a certain temperate Test tube holder – so you don’t burn your hand and it is safe. Step 3 – Set up all the equipment. A- Clamp Stand. B- Measuring tube (25ml) C- Delivery tube D- Conical flask E- Reaction “what’s happening

Formal Lab Report Rates Of Reaction Alkali Metals And Alkaline Earth Metals

1825 words - 8 pages AbstractThe rates of reaction of Alkali metals and Alkaline Earth meatals are compared in this lab. The pH of each of the resulting metal solutions are tested and the products of the reaction between calcium and water is discovered. The tested elements are sodium, lithium, potassium and calcium and each of them were placed in a beaker filled with water. The resulting solutions pH levels were tested with litmus paper. There were more steps for

Rates of reactions

1532 words - 6 pages Experiment: Investigation into the factors that effect the rate of reactionI am going to investigate how different factors affect the rate of a reaction.IntroductionWhat is a reaction? A reaction is when two particles (reactants) join to form a new product or products.What is rate? Rate is a measure of how fast or how slow something is. Rate is a measurement of the change that happens in a single unit of time, any suitable measurement can be

High Rates of Obesity

2428 words - 10 pages less fatty foods full of sugar, salt, and calories are also doable solutions that needs to be implemented to reduce the high rates of obesity. The population of fast food restaurants has increased as the years pass. As a result of this, the rate of obesity have increased significantly in this century. Few people who suffer from diabetes are unable to fit through their house doors as a result of consuming fast foods. Due to the fact that fast food

Uninsured Rates of Hispanics

1756 words - 7 pages children who are younger than 18 years old (21%) are uninsured. This compares with uninsured rates among children who are younger than 18 years of 7.4% among Non-Hispanic whites, 14.5% among African Americans, and 12.4% among Asians. According to the Center for Disease Control and Prevention (2009), Hispanics are the majority population to receive or use much needed medications, including prescription drugs for asthma; cardiovascular disease

Similar Essays

Rates Of Reaction Essay

3996 words - 16 pages Investigation Rates of Reaction InvestigationAim: To investigate the effect of concentration on the rate of reaction between hydrochloric acid, water and magnesium. I am investigating the following reaction: Mg + 2HCl MgCl2 + H2 Magnesium + Hydrochloric Acid Magnesium Chloride + Water During this investigation we will be trying to find out how much affect different concentrations of hydrochloric acid has on the production of hydrogen (product

Rates Of Reaction Investigation Essay

1543 words - 6 pages particles there are per volume of acid. Therefore, more collisions per second will occur and then there will be more successful collisions per second.Temperature of the acid - Rates of reaction increase with a higher temperature because the particles involved in the reaction have more energy to move (from the heat) so they collide more rapidly. This will give more successful collisions per second, and therefore it is essential to keep the

Rates Of Reaction Essay

2549 words - 10 pages were so absurdly small they are all but indiscernible. Stability of conclusion. Obviously, with more time, more readings would have been taken to form a more accurate curve on the graph. However, I believe that sufficient information was recorded to form a firm conclusion and to prove the aforementioned theory to be correct. Bibliography: --------------- * www.purchon.com/chemistry.htm * BBC bitesize revision (online). * Website entitled: - Collisional Theory Of Reaction Rates * The Learning Centre (online.) * Chemistry Textbook.

Rates Of Reaction Essay

2843 words - 11 pages An excellent project, very perceptive -BACKGROUND INFORMATIONWhat affects the rate of reaction?1) The surface area of the magnesium.2) The temperature of the reaction.3) Concentration of the hydrochloric acid.4) Presence of a catalyst.In the experiment we use hydrochloric acid which reacts with themagnesium to form magnesium chloride. The hydrogen ions givehydrochloric acid its acidic properties, so that all solutions ofhydrogen chloride and