• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Classifications of Alcohols Experiment

Extracts from this document...

Introduction

Objective: 1. To differentiate different types of alcohol. Introduction: In organic chemistry, alcohols from the functional group of hydroxyl groups are organic compounds which are characterized by one or more hydroxyl (−OH) groups attached to a carbon atom of an alkyl group (hydrocarbon chain). Alcohols have the general formula CnH2n+1OH (where n represent the number of carbon atom in the compound) or R-OH (where R represent an alkyl group). Alcohols is usually classified into three classes, the primary alcohols (1°), secondary alcohols (2°) and tertiary alcohols (3°).Alcohols fall into different classes depending on how the -OH group is positioned on the chain of carbon atoms. In a primary (1°) alcohol, the carbon which carries the -OH group is only attached to one alkyl group. In a secondary (2°) alcohol, the carbon with the -OH group attached is joined directly to two alkyl groups. In a tertiary (3°) alcohol, the carbon atom holding the -OH group is attached directly to three alkyl groups. The attached alkyl groups may be from the combination of same or different groups. R = alkyl group The boiling points of the normal alcohols increase regularly with the increase of the molecular weights. The primary alcohols boil at a higher temperature than the secondary alcohols that are isomeric with them. Similarly, the latter have higher boiling points than their tertiary isomerides. ...read more.

Middle

When tertiary alcohol is tested in the other hand, the solution will turn cloudy immediately. The speed of this reaction is proportional to the energy required to form the carbocation. The reaction rate is faster when the carbocation intermediate is more stabilized by greater number of electron donating alkyl group (R-) bonded to the positively charged carbon atom while less substituted alcohol reacts much more slowly. Thus, a tertiary alcohol reacts fastest followed by secondary alcohol while primary alcohol generally reacts very slowly. From the experimental results obtained, we know that 2-methyl-2-propanol is a tertiary alcohol (3° alcohol) because this alcohol reacts immediately when Lucas reagent is added to form 2 layered-solution which is cloudy. 2-butanol is a secondary alcohol (2° alcohol) where it took around 7 minutes to form a cloudy solution while n-butanol and alcohol X are primary alcohols (1° alcohol) as they did not react significantly after 15minutes. The equations for the reactions of different alcohols used are as below:- 2-methyl-2-propanol (3° alcohol): ZnCl2 (CH3)3COH + HCl (CH3)3CCl + H2O (2-methyl-2-propanol) (2-chloro-2-methylpropane) 2-butanol (2° alcohol): ZnCl2 CH3CH(OH)CH2CH3 + HCl CH3CHClCH2CH3 + H2O (2-butanol) (2-chlorobutane / 2-butyl chloride) n-butanol (1° alcohol): ZnCl2 CH3CH2CH2CH2OH + HCl CH3CH2CH2CH2Cl + H2O (n-butanol) (1-chlorobutane / n-butyl chloride) Despite the fact that the experimental results obtained are accurate, 2-butanol took a longer time to react as compared to the theoretical results where it should react in within 5 minutes. ...read more.

Conclusion

Besides, addictive need to be added to the ester to produce a stronger pleasant, often fruit smell. Esters are widely used in the fragrance and flavour industry. It is also used in the organic chemistry for the test of alcohols and carboxylic acid. The equation of the chemical reaction that occurred is shown as follows: Concentrated HCl CH3CH2OH + CH3COOH CH3COOCH2CH3 + H2O (Ethanol) (Ethanoic acid) ? (Ethyl ethanoate) Precautionary steps: 1. Keep all the alcohols from any source of fire as alcohols are highly flammable. 2. All the unused or used waste materials must be poured into a specific waste container prepared in the fume chamber to prevent pollution to the environment. 3. Cautions must be taken when pouring concentrated sulphuric acid as it is toxic and is destructive to mucus membrane. 4. 2-methyl-2-propanol is harmful if inhaled. May cause skin and respiratory irritant. Severe eye irritant. 5. All transfer of chemicals should be done in the fume chamber to avoid inhalation of any chemicals vapour as it may cause severe sickness such as cancer. Conclusions: From the experiment, it can be concluded that n-butanol and the unknown alcohol X are primary alcohol, 2-butanol is a secondary alcohol and 2-methyl-2-propanol is a tertiary alcohol. Primary alcohol will undergo oxidation but react slowest in halogen substitution reaction. Secondary alcohol in the other hand undergoes oxidation reaction but will react with a medium speed under halogen substitution reaction. Tertiary alcohol will not undergo oxidation reaction but will react almost immediately in halogen substitution. Alcohols will react with carboxylic acid to form an ester. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Organic Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Organic Chemistry essays

  1. Marked by a teacher

    Experiment to determine the ethanol content of wine

    5 star(s)

    Mass of ethanol (g) Density (g/cm3 ) 0 46.285 26.583 0.9975 1 46.224 26.522 0.9952 2 46.197 26.495 0.9942 3 46.168 26.466 0.9931 4 46.120 26.418 0.9913 5 46.086 26.384 0.9900 6 46.048 26.346 0.9886 7 46.014 26.312 0.9873 8 45.984 26.282 0.9862 9 45.947 26.245 0.9848 10 45.915 26.213 0.9836 11 45.867 26.165 0.9818 12 45.843

  2. Marked by a teacher

    Reactions of aldehydes and ketones. The purpose of this experiment is to compare ...

    5 star(s)

    After pouring away the solution, there were white solid crystal remaining in the test tube. 5. For propanone, there wer 2 colourless immisible layers formed. 6. Both of the solution became turned warm. Part 2 Treating with 2,4-dinitrophenylhydrazine 7. 2,4-dinitrophenylhydrazine solution was yellow in colour.

  1. Preparation of haloalkane. The purpose of this experiment is to prepare 2-chloro-2-methylpropane from ...

    The setup Part 2: Distillation 18. Organic products from a few groups were poured into a measuring cylinder and the volume measured was recorded. 19. After that, a distillation setup was made and the products were poured into the pear-shaped flask.

  2. Comparing The Enthalpy Change OfCombustion Of Different Alcohols

    + (68.20g?0.387Jg-1K-1?67?C) = 47918.00J We can calculate the new enthalpy change of combustion of ethanol incorporating the error: ?Hc = (Energy transferred/Mass of fuel burned) ? Relative molecular mass of fuel = (47918.00J/4.54g) ? 32 = 337748.00 = 338KJ mol-1for Methanol The new change in enthalpy of combustion of methanol will be 328kJ mol-1 +10kJ mol-1 or -10kJ mol-1.

  1. Find the enthalpy change of combustion of a number of alcohol's' so that you ...

    Methanol and Ethanol It is highly flammable and harmful. The vapours will catch fire at temperatures above 13oC. The narcotic effect of ethanol/methanol is well known and may result from inhalation of the vapour. Methanol and ethanol are toxic by inhalation, if swallowed and by skin absorption.

  2. The aim of this experiment is to produce Aspirin. This is an estrification in ...

    hydroxide from the results the mass of aspirin can be calculated followed by the percent purity of the sample. Using this titration it may be difficult to identify the end point because aspirin is a weak acid and the reaction may take longer to complete.

  1. Comparing the enthalpy changes of combustion of different alcohols

    I will now work out how much energy this equates to. During combustion, each CH2 group will create 1 extra CO2 and 1 extra H2O molecule. So, with an extra CH2 group in a chain, an alcohol will give out an extra -1712kJmol-1.

  2. Investigating the Enthalpy Changes of Combustion of Alcohols.

    Most of the combustion reactions in this investigation, especially propanol, butanol and heptanol, involve a lot of carbon. Converting all of the carbon atoms into carbon dioxide molecules requires a lot of oxygen, which was not available from the air around the flame alone. Often, carbon monoxide and carbon (soot)

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work