A Identify the compounds that act as acids in the following

A- Identify the compound(s) that act as acid(s) in the following equilibrium:
NH4+ (aq) + CN (aq) NH3 (aq) + HCN (aq)

B- CT2-L7. Which one of the following oxides would be the most basic?

B2O3, Al2O3, GeO2, Tl2O, Sb2O5

C- Arrange the following acids in order of decreasing acidity: HNO2, HClO, HBrO, HIO4.

NH4+ + CN- <---------> Nh3 + HCN

acid base base acid

The acids are NH4+ and HCN

b) Among the given oxides TL2O is the most basic.

It is the most metallic of the given elements.

C) HIO4 > HNO2 > HClO > HBrO