When a compound is not identified as an acid or salt, is it by default
an acid or does it represent both the acid and the salt? For example,
does the term "residronate" refer to both residronic acid and
residronate sodium, or does it include only residronic acid?

the defination about acid and salt is depend on the H value of this substance.
when the H value >7.0 this is acid;when H value <7.0 this is salt.

so when we mention acid and salt,depend on the H value.even the same
compound in diffrent environment it can be acid or salt.

so for your question,both the acid and the salt.

hopefully can help you. best regards!

there are three or four theories to define acid and bases as follows,

1.Br. Ø. nsted-Lowry Acids and Bases;
2.Lewis Acids and Bases;

(you can download the pdf file here:
www.uiowa.edu/~c004121/notes/ch02_2.pdf)

3.Arrhenius acids and bases (the traditional theory of acids and bases)
http://facultyfp.salisbury.edu/dfrieck/htdocs/212/rev/acidbase/arrhenius.htm

From  hamid reza sedghy on October 5, 2006
When a compound isn?t indentified as an acid or salt, it hasn?t a
default definition for identifying it. The compound may be a base or
its salt or an organic material such as polymers or a neuteral liquid
such as water or alcohol and so on.
In general, prefixes of ?-ate? or ?-ite? or ?-ide? are refer to basic
salts of an acid depending on oxidation state of central atom of acid.
For example, sodium salt of sulfuric acid (H2SO4) is sodium sulfate
and sodium salt of sulfurous acid (H2SO3) is sodium sulfite; sodium
salt of sulfide hydrogen (H2S) is sodium sulfide. Thus, the term
?reidronate? by default always refers to salt of residronic acid not
both of them, and it may refer to residronate potassium or other salt
of this acid, not only residronate sodium.

Its probably called neutral. If the compounds isn't acid a alakli or
base its normally just called neutral..