Does private key belong to one public key in Bitcoin? More address belong to one wallet in Copay. I have a 12-word mnemonic to my old Copay wallet, but not the private key. If I would infer the private key of the 12-word could I reach all the public adresses with that private-key and start withdrawal?
Each private key corresponds to one public key, but a mnemonic key contains the master private key which describes how each private key is generated.
If you want to withdraw from it, I would use Electrum. It can show you the addresses and you can export individual private keys.