Standard qualitative filter paper has an average pore diameter of

PHYSICS · Subjective · A Level · Physics · Measurements and their errors · Measurements and their errors

Problem

25\,\mu\text{m}

. The hydrated radius of a

\mathrm{Na^+}

ion in aqueous solution is approximately

0.20\,\text{nm}

. Approximately how many times larger are the pores than the dissolved ions, and based on this comparison, would filtration separate

\mathrm{Na^+}

from the solution? Provide the numerical factor (rounded to the nearest power of ten) and your conclusion.