Answer:
NH3 weak base
HCOOH weak acid
H3PO4 weak acid
NaOH strong base
Explanation:
When talking about the weakness or strength of acid and bases, it is essential to look at it from the base point of ionization or dissociation in solutions. For an acid or base to be termed strong , this means it ionize completely in solution to form hydroxonium ion and hydroxide jobs respectively in water. For an acid or base to be termed weak, it ionizes only partially in solution.
The strength of acid can be accessed from the value of the acid ionization constant Ka. Strong acids like sulphuric acid have a fairly large value for for this constant while weak acids have a relatively low value for this constant. Hence, we must know that the dissociation equation is not enough to say an acid is weak or strong. Acids with higher Ka value are stronger with acids with lower Ka value.
In likewise manner, we have the base dissociation constant. It is the equilibrium constant for a base dissociation reaction. While stronger bases have relatively higher values for Ka, weak bases have a relatively lower value.
Ammonia yields a weak base solution of ammonium hydroxide in water. This makes it a weak acid
Methanoic or Formic acid like most organic acid is a weak acid. It ionizes only partially in solutions.
Phosphoric acid is also a weak acid as it ionizes partially in solutions too.
Lastly, sodium hydroxide is a strong base as it ionizes completely in solution
