Ethyl alcohol (C2H6O): Properties, molecular structure, application and preparation

by Johnny Jacks
Ethyl Alcohol (Chemical Formula C2H6O): Properties, Molecular Structure, Applications, and Preparation

What is Ethyl Alcohol?

Ethyl alcohol, also known as ethanol, is a colorless liquid obtained through the fermentation of various sources such as rice, cassava, cooked corn, grapes, apples, and more. It is commonly referred to as grain alcohol or simply alcohol, belonging to the organic compound family of alcohols. Ethyl alcohol is highly flammable and is a key component found in alcoholic beverages.

Molecular Formula: C2H6O

Molecular Mass: 46

Molecular Structure:

Simplified Structural Formula: CH3-CH2-OH

Within the ethyl alcohol molecule, there is an H atom that is not bonded to the C atom but is instead bonded to the oxygen atom, forming the -OH group. This -OH group imparts distinctive chemical properties to alcohol.

Physical Properties of Ethyl Alcohol

Ethyl alcohol (C2H6O) exhibits the following physical properties:

  • Ethyl alcohol is a colorless liquid that boils at 78.3 degrees Celsius. It is lighter than water and dissolves infinitely in it.
  • Ethyl alcohol is capable of dissolving many substances, including iodine and benzene.
  • The alcohol strength is defined as the volume of ethyl alcohol present in 100 ml of an alcohol and water mixture. For example, a 100 ml sample of 45-degree alcohol contains 45 ml of pure ethyl alcohol.

The formula for calculating alcohol strength is as follows:

Alcohol Strength = (Vr / Vhh) x 100

Where:

  • dr is the alcohol degree (in degrees).
  • Vr is the volume of ethyl alcohol (in ml).
  • Vhh is the volume of the alcohol and water mixture (in ml).

Complete alcohol content is represented by an alcohol strength of 100%. The higher the alcohol content, the greater the concentration of ethyl alcohol in the solution, and vice versa.

Chemical properties of ethyl alcohol

With the above bonding characteristics, ethyl alcohol has three characteristic chemical properties as demonstrated by the following detailed experiments:

Learn the properties of ethyl alcohol.

Learn the properties of ethyl alcohol.

Chemical Properties of Ethyl Alcohol

Ethyl alcohol exhibits distinct chemical properties, which are exemplified through the following detailed experiments:

1. Strong Reaction with Oxygen when Heated

In this experiment, a few drops of ethyl alcohol are added to a porcelain cup and ignited. Upon ignition, ethyl alcohol produces a blue flame and releases a substantial amount of heat. This phenomenon illustrates the strong reaction of ethyl alcohol with oxygen when exposed to heat, resulting in a combustion reaction.

The reaction occurs as follows:

C2H6O (l) + 3O2 (g) (heat) → 2CO2 (g) + 3H2O (g)

2. Reaction with Sodium

Another experiment involves placing a piece of sodium into a beaker or test tube containing ethyl alcohol. During the course of the experiment, observable air bubbles emerge, and the sodium gradually dissolves. This reaction signifies that ethyl alcohol, akin to water, reacts with sodium, liberating hydrogen gas.

The reaction unfolds as follows:

2C2H5OH (l) + 2Na (s) → 2C2H5ONa (aq) + H2 (g)

This alcohol can also chemically react with strong metals such as potassium (K) or sodium (Na).

3. Reaction with Acetic Acid

In a distinct experiment, ethyl alcohol is combined with acetic acid in test tube A. A small amount of concentrated sulfuric acid is added as a catalyst. The mixture is then boiled for a period and subsequently halted. Following this, a small quantity of water is added to the condensate in test tube B, gently shaken, and observed.

The observed phenomenon involves the presence of a colorless, aromatic liquid in test tube B, which is insoluble in water and floats atop it. This observation validates that ethyl alcohol reacts with acetic acid to yield ethyl acetate. This resulting liquid possesses a pleasant fragrance and exhibits slight solubility in water, making it suitable for use as an industrial solvent.

The reaction proceeds as follows:

C2H5OH + CH3COOH → CH3COOC2H5 + H2O (In the presence of concentrated H2SO4, at elevated temperature)

Two Methods of Preparing Ethyl Alcohol

Depending on the intended application, ethyl alcohol can be prepared using two distinct methods:

Learn how to prepare ethyl alcohol.

Learn how to prepare ethyl alcohol.

Method 1: Preparation of Ethyl Alcohol for Beverage Consumption

In the production of ethyl alcohol for use as a beverage, individuals typically employ starch or glucose as the primary starting materials. This process involves the catalytic action of yeast, leading to the formation of ethyl alcohol, as illustrated by the following equation:

Starch/sugar (yeast) → Ethyl alcohol

Method 2: Production of Industrial-Grade Ethyl Alcohol

When the objective is to manufacture ethyl alcohol for industrial purposes, the process differs. In this method, ethylene is combined with water, and an acid serves as the catalyst. The chemical reaction occurs as follows:

CH2 = CH2 + H2O (acid) → C2H5OH

Note: Organic compounds that feature the presence of the OH group, sharing the general molecular formula CnH2n+1OH, fall into the category of monosaturated alcohols or alkanols. These compounds exhibit properties similar to those of ethyl alcohol.

Applications of Ethyl Alcohol

Ethyl alcohol, aside from its prevalent use as a beverage, serves various vital additional purposes:

Raw Materials in Pharmaceutical, Synthetic Rubber, and Acetic Acid Production

Ethyl alcohol is a crucial raw material in the production of pharmaceuticals, synthetic rubber, and acetic acid.

Solvent in Varnish and Perfume Preparation

It finds extensive use as a solvent in the formulation of varnishes and perfumes.

Alcohol Fuel and Industrial Processes

Ethyl alcohol is employed as a fuel, often blended with gasoline, and plays a role in numerous industrial processes. Its characteristic of having a low freezing point also makes it suitable for use in antifreeze products.

Disinfection and Antibacterial Cleaning

Solutions containing 70% ethyl alcohol are utilized for disinfection purposes, including in the production of widely-used antibacterial cleaning gels at a 62% concentration. Ethyl alcohol is highly effective as an antiseptic at around 70% concentration. Higher or lower concentrations exhibit reduced antibacterial efficacy. Ethyl alcohol eliminates microorganisms primarily by denaturing their proteins and dissolving their lipids. Moreover, it is effective against various bacteria, fungi, and many viruses, albeit less effective against bacterial spores.

Ethyl alcohol exercises.

Ethyl alcohol exercises.

The above article has furnished comprehensive information on the properties, molecular structure, applications, and preparation of ethyl alcohol (C2H6O), a substance ubiquitously present in our surroundings. This knowledge is intended to equip you with valuable insights applicable both in learning and practical contexts.

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