The spectator ions in the reaction between aqueous perchloric acid and aqueous barium hydroxide are . OH- and ClO4- H , OH- , ClO4-, and Ba2 H and OH- H and Ba2 ClO4- and Ba2

ClO4-, and Ba2+.

Explanation:

A spectator ion is an ion that exists as a reactant and a product in a chemical equation.

Equation of the reaction.

2HClO4 + Ba(OH)2 --> Ba(ClO4)2 + 2H2O

ClO4- + OH- --> 2ClO4- + H2O

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

solute : a solute is a substance that is dissolved in another substance is known as a solvent. it is mixed with a special mixture know as homogeneous mixture.

solvent: a solvent is a substance that dissolved a solute, which results in a solution is known as solvent.