What is the Latin equivalent of "context" (as a noun) and of
"Knowledge is in context"?

"Context" is a masculine noun, "contextus."
The translation of the phrase above would be "Scientia in contexto
est." (Scientia is pronounced "ski-EN-tia").

Contextus is fourth declension masculine, declined as follows:

contextus - nom. sing.
contextus - gen. sing.
contextui - dat. sing.
contextum - acc. sing.
contextu  - abl. sing.

The preposition "in" requires the ablative. ("in contextu operis
dicemus," Tacitus.) Thus, the correct translation is "scientia in
contextu est."

hlabadie-ga