Which Substance Acts as an Acid or Base in These Cases?

[transgalactic]

how to know which of these substances will act as an acid
and which one will act as a base??

case A:
CHOOH +H_2O

case B:
NH_3 +H_2O

 

[danago]

Do you know the systematic name of the first substance? Thats a give away ;)

 

[transgalactic]

i don't know there names
but i do know that what act as an acid
in one of them
?