You are probably thinking of alkanes of the form CnH2n+2. They have been named as large as C(100)H(202).
According to an archived entry in Wikipedia, which seems to make sense to me:
" ..at absolute zero, you could actually make a hydrocarbon chain infinitely long (as long as you have enough stuff). But in practice, when you can't actually get to absolute zero, there's a theoretical upper limit on how long you can make the chain due to entropy. That is, the higher the temperature and the longer the chain, the less stable it is."
Is it possible to keep adding C and H atoms to make longer and longer chains to an infinite number?
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