Question

Example of bivalent acidic radicals

Answer 1

The ion formed after removal of Hydrogen ion from an acid is called as Acidic Radical.
For example:
when HCl loses  H⁺  ion from acid . we get Cl⁻ which is an acidic radical -- which is monovalent.

Bivalent means the acid should lose 2 H+ ions.

example:
H2SO4 :
From H2SO4 loses 2 H⁺ ions, so we get, SO₄⁻²

Carbonic acid.
H2CO3
H2CO3 loses 2H⁺ ions we get CO₃⁻²

Answer 2

In chemistry bivalent refers to an element whose atom can replace 2 atoms of hydrogen or other univalent element. It also refers to a radical that has the same valence as a bivalent atom.

For example, calcium in its chlorid CaCl2 replaces 2 atoms of hydrogen in hydrochloric acid HCl

the bivalent radical methylen CH2 in its chlorid CH2Cl2 shows the same valence.

Bivalent radicals derived from univalent acyclic hydrocarbon radicals whose names end in '-yl' by removal of 1 or 2 hydrogen atoms from the carbon atom with the free valences are named by adding '-idene' to the name of the corresponding univalent radical.

For example, Ethylidene, Vinylidene, Isopropylidene.