organic chem (pg 46)

Question 1

processes to manufacture ethanols

Answer 1

• Add steam to ethene (phosphoric acid catalyst, 300 degree celcius)
  eg C2H4 + H2O —> C2H5OH
• Fermentation by adding yeast to sugar solution. (Yeast contains enzymes that convert sugar to ethanol)

Question 2

process of Fermentation in ethanol

Answer 2

Adding yeast to sugar solution

sugar —> ethanol + carbon dioxide

C6H12O6(aq) —> 2C2H5OH(aq) + 2CO2(g)

conditions: absence of O2, 20-35 degree celcius or specifically 37 degree celcius. Yeast will be killed if temperature is too high, whereas the enzymes will be denatured if the temperature is too low.

product is a mixture of ethanol and water. ethanol is separated via fractional distillation after removing the yeast by filtration.

Question 3

uses of fermentation

Answer 3

• to make alcoholic drinks such as beer
• as a fuel for motor vehicles
• as a solvent for organic compounds that are volatile or have low boiling points

Question 4

chemical reactions in carboxylic acids

Answer 4

Esterification (the process of combining an organic acid with an alcohol to form an ester and water)

conditions: warmed with concentrated sulphuric acid catalyst

alcohol + carboxylic acid —> ester + water

name of ester: __yl(alcohol), __oate(acid)

ester: sweet smelling volatile liquid