Primary focal hyperhidrosis does not cause illness. Basically, you just sweat excessively. Although it is a medical condition, it's not a sign of disease or a drug interaction. People who have it are otherwise healthy. The symptoms of primary focal hyperhidrosis are fairly specific.
Potassium iodide is a component in the electrolyte of dye sensitized solar cells (DSSC) along with iodine. Potassium iodine finds its most important applications in organic synthesis mainly in the preparation of aryl iodides in the Sandmeyer reaction, starting from aryl amines.
#0.75 g#. Notice that you were given the solution's mass by volume percent concentration, which is defined as mass of solute divided by volume of solution, and multiplied by #100#. In your case, a #3.0% w/v# potassium iodide solution will contain #3.0 g# of potassium iodide for every #100 mL# of solution. You know that the volume of the sample is four times smaller than this value, so you can say right from the start that it will contain four times less potassium iodide.