Calculate the molarity of a solution made by adding 35.0 ml of concentrated perchloric acid (70.5 % by mass, density 1.67 g/ml) to some water in a volumetric flask, then adding water to the mark to make exactly 2000 ml of solution. (it is important to add concentrated acid or base to water, rather than the other way, to minimize splashing and maximize safety.)

Molarity is equal to the number of moles of solute per liter solution.

number of moles solute: (molar mass of perchloric acid is 100.45 g/mol)
35.0 mL * (1.67 g/mL) *0.705 * (mol/100.45 g) = 0.41 moles
liter solution = 2000 ml * (1 L/1000 ml) = 2 L

molarity is equal to 0.41 moles/ 2 L  =0.205 M

Thus, molar volumes of the liquids are expected to be closer to those in the "solid state."

Explanation:

Anything which occupies mass is known as the matter and we know that matter is existed in three states i.e. solid, liquid and gas. The atoms in the solid are closely packed and therefore, they posses very less kinetic energy. The atoms in liquid state are less closely packed and possess more kinetic energy in comparison to the solid state. The atoms in the gaseous state are loose and possess maximum kinetic energy. The molar volume is the volume occupied by 1 mole of a substance. Solid being compressed will have lesser volume in comparison to the liquid and liquid will have lesser volume in comparison to the gas.

In the solid state, it is expected that the amount of empty space is less than that of the gaseous state, and molar volumes are influenced by molecular characteristics. Thus, solid state molar volumes are not similar to those in the gaseous state. When, comparing empty space in the liquid state, it is expected that space in the liquid phases is less than space in the gaseous phase and equivalent to space to the solid state. Thus, molar volumes of the liquids are expected to be closer to those in the solid state.