Why is this cationic? please help ?

Question

The book says:

H2SO4 + Zn ZnSO4 + H2

CATIONIC SINGLE REPLACEMENT

I am struggling with cationic and anionic single replacements. Why is this cationic and what would be an anionic single replacement?

Answer 1

In H2SO4 H+ is the cation and SO4^2- is the anion so it's a cationic single replacement reaction because Zn is replacing the cation H+ in H2SO4.

Anionic would be:

NaI + Cl2===>NaCl + I2

In this case it is an anionic single replacement reaction because in NaI the cation is N+ and the anion is I- and in this reaction Cl is replacing the anion I- in the compound NaI.