Question

An "extensive property" is a material property that depends on the amount of material present in a sample. An "intensive property" is a material property that depends only on the type of material in a sample and not on the amount. Is the rate of reaction of a chemical species, n, an extensive property or an intensive property? Explain. How would you classify the rate of generation of a chemical species, G?

Answer 1

Answer: Rate of reaction is an "extensive property". Rate of generation of a chemical species is an "intensive property"

Explanation:

• Let´s check out the Factors that affect the speed of reactions:

Temperature, Physical state of the reagents, Presence of a catalyst, Pressure, light, Concentration of the reagents.

When having a general chemical reaction like this:

aA + bB → cC + dD

Usually the rate of reaction is represented by the next equation

$Rate = k [A]^{x} [B]^{y}$

Where k= constant

x, y = reactant orders

A, B = reactant concentration

As we can see in the last equation, the rate of reaction depends directly of the amount of material present in a sample, that is why it is an "extensive property"

• The rate of generation of a chemical species, depends of other factors like  Temperature, Presence of a catalyst, Pressure. As we can see all the factors that allow the speed of generation of a new chemical species let us know that this is an intensive property because it doesn´t depends of the amount of material.