Combustion

Question 1

Explain the concept of a mole

Answer 1

A mole is a number of atoms that is equal to the number of atoms in 0.012kg of carbon-12. In other words the weight of a mole is equal to 1Kg x the relative atomic mass of that atom. Oxygen has a relative atomic mass of 16 so one mole of oxygen is equal to 16kg.

Question 2

Explain the concept of relative atomic mass and relative molecular mass.

Answer 2

Relative atomic/molecular mass is the weight of an atom/molecule measured in units of hydrogen atoms. Because hydrogen is the lightest atom it has a relative atomic mass of 1. A carbon atom weighs 12 times as much as a hydrogen atom and so has a relative atomic mass of 12.

Question 3

Explain the calorific value of fuel

Answer 3

It is the number of megajules of heat produced by full combustion of a kilogram of a given fuel.

Question 4

How do you calculate the volume of a gas?

Answer 4

Avogadros law states that the volume occupied by a Kilomole of any gas is the same for all gases under a given temperature and pressure. A kilomole of gas under standard atmospheric pressure (1.013 bar) and 0 degrees C occupies 22.4m^3.

A kilomole of ozone occupies the same volume as a kilomole of 02 but weights half as much.

Question 5

What is the ideal gas law?

Answer 5

(Pressurevolume)/(numbertemperature)=Constant

Volume = (number of molestemperature (Kelvin)constant)/pressure