De or het waterchocolade?

The correct Dutch article is:

de waterchocolade

Rule Words ending in -ade: always de. See the rule

How to use waterchocolade

the waterchocoladede waterchocolade
this waterchocoladedeze waterchocolade
that waterchocoladedie waterchocolade
our waterchocoladeonze waterchocolade
your waterchocoladejouw waterchocolade
every waterchocoladeelke waterchocolade
which waterchocolade?welke waterchocolade?
a big waterchocolade / the big waterchocoladeeen grote waterchocolade, de grote waterchocolade