What's the difference between all and each?

Question

What is the difference between these sentences:

1. All experiments are carried out four times
2. Each experiment is carried out four times

and which one should I use if I want to say I carry out the 1st experiment four times, the 2nd experiment four times, and so on..

Answer 1

Using "All experiments..." seems to imply that the experiments are carried out as a group. On the other hand, it seems as though you want to talk about four separate experiments that are each carried out four times, in which case "Each experiment..." would be the preferred construction.