3. and 5. Looks like Tradescantia sp. different varieties. Common name..... see link. I do not think that it is politically correct to use this common name any more, but everybody knows it by this name.
1. There are several plants that start with leaves that look like yours and then they evolve as they grow. So,I will not risk giving you my thought incase I am wrong!
4. Again not sure. I believe it MAY be an Impatiens sp. If so it will flower. Please add more pics here later when it does, for confirmation if needed.
#1 looks like a small elephant ear plant to me. If so you should have a small tuber in the pot instead of a root ball. If grown in stronger light, the leaves would get much larger.
Just a guess, but the leaves and stalk are the right color and shape.