Question

# Consider 1 g of solid material with density 2.5 g/mL or 2.5 g/cm³. First shape it into a single sphere, compute the specific surface area (SSA) as cm²/g. Now divide

this material into two equal parts and shape into two spheres, again compute the specific surface area in cm?/g. Repeat the process of dividing each sphere into two repeatedly and computing the specific surface area till you obtain particle diameters in the range of microns (1 µm =Use a spreadsheet for this exercise: put the number of spheres in the first column,the volume of each sphere in the second, the diameter of each sphere in the third,the surface area of each sphere in the fourth, and finally the specific surface area,SSA (product of column 1 and 4) in column 5. Plot SSA versus particle diameter -notice the exponential increase in SSA as diameter decreases. Consider the effects of surface forces relative to downward gravitational force for colloidal particles!Look at the solutions for Homework 2 to get a handle on this problem10-6 m) made from the same 1 g mass. (a) You are really comfortable with using a spreadsheet (b) That you are completely familiar with the speciation of the most common weak acid system in nature - the carbonic acid system, and (c) That you know why surface waters suffer from turbidity problems due to the presence of natural colloids (like clays and silts) that often have a negative charge associated with them so that surface forces like electrostatic repulsion dominate the downward gravity settling force

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