An aqueous solution is 3.50% by mass potassium bromide, KBr, and has a density of 1.02 g/mL. The molarity of potassium bromide in the solution is

Awhite powder is added to a solution. the images show observations made before the powder is added, just after the powder has been added, and a little while later. (the liquid in the small beaker is phenol red solution.) what evidence shows that a chemical change has taken place?