You have a 100 ml stock solution of 100 mg/ml ampicillin in deionized water. You want to make 30 ml of 25 mg/ml ampicillin in deionized water. How much ampicillin stock and how much deionized water are needed to make this

The amount of  ampicillin stock is  

The amount of deionized  is 22.5 \ mL

Explanation:

From the question we are told that

   The volume of stock solution of ampicillin in de-ionized water is

   The concentration (in mg ) of ampicillin in de-ionized is

    The volume of ampicillin in deionized water to produce is

The concentration (in mg )  of ampicillin in de-ionized water to produce is

The chemical process can be mathematically represented as

=>          

The amount of  ampicillin stock is   and amount of 25 mL  (30 - 7.5 = 22.5 mL ) of deionized water

to make a supersaturated solution, make a saturated solution of sugar by adding 360 grams of sugar to 100 ml of water at 80 degrees celsius. when the water cools back down to 25 degrees, that 360 grams of sugar will still be dissolved even though the water should only dissolve 210 grams of sugar.