# Acids that donate just one proton

• What is the general name for acids that can only lose one hydrogen ion? (i.e. $\ce{HCl}$)
• What is the general name for acids that can lose $n$ hydrogen ions? (i.e. $\ce{H_3PO_4}$, which can lose 3)

The answers to these questions are probably mentioned a million times on the internet, but I could not find them.

An acid that can donate one hydrogen ion is called monoprotic (i.e., $\ce{HCl}$). An acid that can donate two is called diprotic (i.e., $\ce{H_2SO_4}$). An acid that can donate 3 is called triprotic ($\ce{H_3PO_4}$). I don't know of any which can donate four.
• An acid that can donate $n$ protons is called polyprotic, assuming $n > 1$. – Eric Brown Jun 3 '13 at 19:33
• @EricBrown And assuming $n \in \mathbb{N}$. ;-) – Tim Vermeulen Jun 3 '13 at 20:07