When an iron nail is added to a copper sulfate solution, the blue color begins to disappear from the solution and brown flakes appear on the nail. The incomplete equation for the reaction is Fe + CuSO4 → FeSO4 + X. What is X in the equation? A) Cu B) CuO C) CO4 D) CuO2

Asample of the male sex hormone testosterone, c19h28o2, contains 3.88×10^21 atoms of hydrogen.(a) how many atoms of carbon does it contain? (b) how many molecules of testosterone does it contain? (c) how many moles of testosterone does it contain? (d) what is the mass of this sample in grams?

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.

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?