In a solution of H2SO4, rank the concentration of H2SO4, H+, SO42- from highest concentration to lowest concentration.

Explanation:

H₂SO₄ is a strong acid, which means that most of it ionizes in aqueous solution.

Since it is a diprotic acid (two hydrogen ions) its ionization occurs in two steps:

Thus, almost all H₂SO₄ has ionized and its final concentration is almost nothing.

After the first ionization, the conentrations of H⁺(aq) and HSO₄⁻ are equal but by the second ionization more H⁺ ions are produced along with SO₄⁻.

You can show it as one step dissociation, assuming 100% dissociation (given this is a strong acid):

By the stequiometry you can build this table:

                 H₂SO₄ (aq) → 2H⁺(aq) + SO₄²⁻(aq)

Initial                A                 0              0

Change           - x               +2x          +x

Equilibrium       A - x           2x             x

As explained, A - x is very low, and 2x is twice x. Thus,

The rank of the concentrations from highest to lowest is:

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."