Chapter 20, Problem 45A

Interpretation Introduction

Interpretation:

The equation for fermentation of glucose to ethanol is written and concentration of ethanol solutions related to fermentation is to be discussed.

Concept introduction:

Fermentation is chemical breakdown of a substance by micro-organisms, bacteria or yeasts.

The fermentation of glucose in presence of yeast produces ethanol.

Answer to Problem 45A

Chemical equation:

  $C_6{H}_{12}{O}_6\stackrel{}{{\displaystyle \stackrel{yeast}{\to }}}2C_2{H}_{5}OH+2C{O}_2$

After 13% concentration, yeast can’t survive.

By distillation, ethanol content can be increased.

Explanation of Solution

On fermentation of glucose by yeast, it is converted into ethanol and carbon dioxide gas is released which produces effervescence.

  $C_6{H}_{12}{O}_6\stackrel{}{{\displaystyle \stackrel{yeast}{\to }}}2C_2{H}_{5}OH+2C{O}_2$

The13% ethanol content can be produced by this method because after this concentration, yeast can’t work. So to increase the ethanol content, distillation of fermentation mixture is done.

Conclusion

Thus, ethanol can be produced by fermentation of glucose in presence of yeast.