Mixture or substance?

A mixture is defined as 2 substances that are arbitirarily combined. They are either homogenous or heterogenous.

A substance is defined as being homogenous and has definite, fixed composition that is NOT arbitrary.

On some classwork we did, this following was stated as being true:

sodium chloride is a...... answer: mixture

I disagree; wood is a substance because it has a fixed composition by definition. And since sodium chloride is a compound, it is not a mixture either; it is a substance.
the choices for classification on the worksheet was "mixture" or "substance".

thanx

Pengwuino
Gold Member
Wood is not a substance. There is no chemical compound that can be called "wood". A wood is a large mixture of various chemicals and compounds.

thank you!!!!

How about sodium chloride then? it is a substance?

Pengwuino
Gold Member
Yes.. its ordinary table salt.

Think of it this way, a substance can not be physicly broken down into somthing else.

A mixture can be physicly seperated (Like filtering a mixture)