Answer
${NO_3}^-$ doesn't act as a weak base.
Work Step by Step
1. Protonate this anion, to get its conjugate acid:
${NO_3}^- --\gt HNO_3$
2. Analyze the protonated compound.
- Strong acids have insignificant bases as conjugate pair.
- H{NO_3} is a strong acid, therefore, ${NO_3}^-$ has an insignificant basicity.
- So, ${NO_3}^-$ doesn't act as a weak base.
