Usage patterns
〈人〉にチョコレートをあげるto give someone chocolate (e.g. on Valentine's Day)
I gave chocolate to the person I like on Valentine's Day.
チョコレートが溶けるfor chocolate to melt
The chocolate melted in the hot car.
〈物〉にチョコレートをかけるto drizzle/coat something with chocolate
I poured chocolate over the ice cream and ate it.