Collective nouns refer to a group of people, animals, or things. Examples include:
* Team (group of people)
* Flock (group of birds)
* Pack (group of wolves)
"Hand" is a singular noun, referring to a part of the body.
You might be thinking of the phrase "a hand of bananas", which is a colloquial way of referring to a bunch of bananas. However, "hand" is not technically a collective noun in this instance.