Question

Ethanol burns in air with a:
(A) Blue flame
(B) Sooty flame
(C) Red flame
(D) Yellow flame

Answer 1

Hint: Ethanol is a volatile, flammable, colorless liquid with a slight characteristic odor. It is also called pure alcohol. When one hydrogen atom at the ethane molecule is replaced by one hydroxyl, the ethane changes to ethanol.

Complete step by step answer:
Let us see how ethanol is produced.
Ethanol can be made from any crop or plant that contains a large amount of sugar or components that can be converted into sugar, such as starch or cellulose.
Ethanol production process includes milling the corn to meal, liquefying the metal by adding water and cooking. Thus by breaking down starch into sugar, using yeast to ferment the sugar to ethanol, the last step would be distilling the ethanol by boiling and condensing it by residual water.
${ C }_{ 2 }{ H }_{ 4 }+{ H }_{ 2 }O\longrightarrow { C }_{ 2 }{ H }_{ 5 }OH+heat\quad energy$
Now, let us consider the question.
Burning ethanol has a flame that is mostly blue with yellow accents. It can be quite hard to see. The flame temperature itself is relatively low, but not as low as with methanol. Complete combustion produces the typical blue flame caused by excited carbon dioxide.
${ C }_{ 2 }{ { H }_{ 5 }OH+3{ O }_{ 2 }\longrightarrow 2{ CO }_{ 2 }+3{ H }_{ 2 }O+heatenergy }$

Hence, Ethanol burns in air with a blue flame. Therefore, option A is the required answer.

Note: Even though ethanol is a very commonly used alcoholic drink, it is a dangerous chemical if consumed in pure state. While ethanol is consumed when drinking alcoholic beverages, consuming ethanol alone can cause coma and death.