Yes, family is used as a collective noun, for example a family of five, a family of actors, a family of gophers, etc.
There is no specific collective noun for 'five members'. However if the 'five members' are people, then any suitable collective noun for people will work; for example:a family of five membersa committee of five membersa board of five membersan assembly of five membersa congregation of five members
Shoal is a collective noun. It is the collective noun for fish. A shoal of fish.The collective noun is a mint of candies
There is no specific collective noun for the noun vowels, in which case a noun suitable for the situation can be use, for example a group of vowels, a string of vowels, a bunch of vowels, etc.
500 sheets = a ream of paper.
There is no standard collective noun for a group of reflections. The noun 'reflection' is not a standard collective noun.
No, the noun lumber is not used as a collective noun. The collective noun for lumber is a stack of lumber.
No, the noun farm is not a collective noun.
No it is not a collective noun.
The collective noun is a series of explosions.
No, the noun land is not a collective noun. However, any noun can function is as a collective noun in a suitable context without being a designated collective noun.
No, games is not a collective noun. The collective noun for games is 'a compendium of games'.