Question

Write the chemical reactions involved in the manufacture of ethyl alcohol form sucrose.

Short answer

Question: Describe the chemical reactions involved in the manufacture of ethyl alcohol from sucrose. Answer: The manufacture of ethyl alcohol from sucrose involves two main steps. First, sucrose is hydrolyzed into glucose and fructose by invertase or heating with dilute acid. The reaction is: C12H22O11 (Sucrose) + H2O -> C6H12O6 (Glucose) + C6H12O6 (Fructose). Next, glucose and fructose undergo fermentation by yeast enzymes, producing ethanol and carbon dioxide. The reaction is: C6H12O6 (Glucose/Fructose) → 2C2H5OH (Ethanol) + 2CO2 (Carbon dioxide). Combining both reactions gives: C12H22O11 (Sucrose) + H2O -> 2C2H5OH (Ethanol) + 2CO2 (Carbon dioxide).

Step-by-step solution

Hydrolysis of Sucrose

The first step in the production of ethyl alcohol from sucrose is its hydrolysis into glucose and fructose. Sucrose can be hydrolyzed by an enzyme called invertase or by heating with dilute acid. The reaction is as follows: C12H22O11 (Sucrose) + H2O -> C6H12O6 (Glucose) + C6H12O6 (Fructose)

Fermentation of glucose and fructose

The next step involves the fermentation of glucose and fructose to produce ethanol (ethyl alcohol) and carbon dioxide. This process is carried out by yeast, which contains enzymes that facilitate the breakdown of glucose and fructose into ethanol and carbon dioxide. The fermentation reactions for both monosaccharides are similar and can be summed up as follows: C6H12O6 (Glucose/Fructose) → 2C2H5OH (Ethanol) + 2CO2 (Carbon dioxide) In summary, the combined reactions for the manufacture of ethyl alcohol from sucrose can be written as: C12H22O11 (Sucrose) + H2O -> 2C2H5OH (Ethanol) + 2CO2 (Carbon dioxide)

Key concepts

Hydrolysis of Sucrose

The journey of manufacturing ethyl alcohol begins with the hydrolysis of sucrose. Sucrose, a disaccharide, must first be broken down into simpler sugar units—glucose and fructose—before it can be fermented. This process occurs through a reaction with water, a transformation often catalyzed by an enzyme called invertase or through heating with a dilute acid. The process can be depicted as follows:

C12H22O11 (Sucrose) + H2O → C6H12O6 (Glucose) + C6H12O6 (Fructose)

The breakdown of sucrose is essential as it allows yeast to access fermentable sugars. Understanding hydrolysis is a cornerstone of biochemistry and showcases the significance of water in chemical reactions. This step transforms a non-fermentable sugar into two fermentable ones, setting the stage for the production of alcohol.

Fermentation Process

With glucose and fructose available post hydrolysis, the fermentation process takes the stage. Fermentation is an anaerobic process, where yeast converts sugars into ethanol (ethyl alcohol) and carbon dioxide, without the need for oxygen. The process is natural and has been harnessed for centuries in alcohol production. The general chemical reaction facilitated by yeast enzymes is:

C6H12O6 (Glucose/Fructose) → 2C2H5OH (Ethanol) + 2CO2 (Carbon dioxide)

Important to note is that while the yeasts are the heroes of this process, the temperature, pH, and the absence of oxygen are critical factors influencing the rate and efficiency of fermentation. This process not only yields alcohol but is also key in baking and the production of biofuels.

Enzymatic Conversion

In both the hydrolysis and fermentation stages, enzymes play a pivotal role. These biological catalysts speed up chemical reactions without being consumed in the process. In the hydrolysis of sucrose, the enzyme invertase splits sucrose into glucose and fructose. During fermentation, various yeast enzymes, such as zymase, convert glucose and fructose into ethanol and carbon dioxide. The enzymatic conversion ensures that these reactions occur under mild conditions, which is essential for preserving the yeasts' viability and ensuring a high yield of ethanol. The specificity and efficiency of enzymes make them invaluable in the industrial production of ethyl alcohol.

Chemical Reactions in Alcohol Production

The production of ethyl alcohol is a beautiful choreography of chemical reactions. It showcases the transformation of complex organic molecules into simpler ones, releasing energy and desired by-products along the way. The hydrolysis of sucrose to glucose and fructose and their subsequent fermentation to ethanol and carbon dioxide are prime examples of chemical reactions that are both fundamentally interesting and industrially important. These chemical processes are defined by stoichiometry, catalysts like enzymes, and reaction conditions that ensure efficiency and yield. Overall, these chemical reactions not only fuel the beverage industry but also play a crucial role in the energy sector through biofuel production.