Question

When ethanol, C2H5OH (a component in some gasoline mixtures) is burned in air, one molecule of ethanol combines with three oxygen molecules to form two CO2 molecules and three H2O molecules.


A) Write the balanced chemical equation for the reaction described.


B) How many molecules of CO2 and H2O would be produced when 2 molecules ethanol are consumed? Equation?


C) How many H2O molecules are formed, then 9 O2 molecules are consumed? What conversion factor did you use? Explain!


D) If 15 ethanol molecules react, how many molecules O2 must also react? What conversion factor did you use? Explain!

Answer 1

Answer:

1) C2H5OH(l)+3O2(g)⟶2CO2(g)+3H2O(l)

2) four molecules of CO2 will be produced and six molecules of water

3)9 molecules of water are formed when 9 molecules of oxygen are consumed.

4) 45 molecules of oxygen

Explanation:

The balanced chemical reaction equation is shown here and must guide our work. When ethanol is burned in air, it reacts as shown;

C2H5OH(l)+3O2(g)⟶2CO2(g)+3H2O(l)

Hence, if we use 2 molecules of ethanol, the balanced reaction equation will look like this;

2C2H5OH(l)+6O2(g)⟶4CO2(g)+6H2O(l)

Hence four molecules of CO2 are formed and six molecules of water are formed

From the balanced stoichiometric equation;

3 molecules of oxygen yields 3 molecules of water

Therefore, 9 molecules of oxygen will yield 9 × 3/3 = 9 molecules of water

Therefore, 9 molecules of water are formed when 9 molecules of oxygen are consumed.

From the reaction equation;

1 molecule of ethanol reacts with 3 molecules of oxygen

Therefore 15 molecules of ethanol will react with 15 × 3/1 = 45 molecules of oxygen