Answer: Reactivity is not a physical property, it is a chemical property.
Explanation:
Physical property is a value of matter that can be observed and measured without any change in composition of the matter. Examples of physical properties are color, combustion,melting point,boiling point,solubility, texture, appearance, polarity, odor,viscosity, density and many more.
Chemical properties are characteristics that are obvious or seen when substances undergo chemical reaction. Examples are reactivity,toxicity, acidity, flammability, and heat combustion.
HClO4 +NaOH -----> NaClO4 + H2O
moles of NaOH = (0.0832 x 50 ) /1000= 4.16 x10^-3 moles
since the mole ratio of HClO4 to NaOH is 1:1 the moles of HClO4 is also 4.16 x 10^-3 moles
volume of HClO4 is therefore = moles/ molarity
that is 4.16 x 10^-3mol/ 0.167 mol/L= 0.0249L
multiply by 1000 to convert to ml
0.0249 x 1000= 24.9 ml