How many milligrams of sodium fluoride are needed to prepare 100 ml of a sodium fluoride stock solution such that a solution containing 2 ppm?

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

What is the independent variable in this investigation? mass volume sample number substance density

Achemistry student needs to standardize a fresh solution of sodium hydroxide. he carefully weighs out of oxalic acid , a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in of distilled water. the student then titrates the oxalic acid solution with his sodium hydroxide solution. when the titration reaches the equivalence point, the student finds he has used of sodium hydroxide solution.calculate the molarity of the student's sodium hydroxide solution. be sure your answer has the correct number of significant digits.