Air is made up of different gases, such as oxygen, nitrogen, and carbon dioxide. Which statement best describes these three components of air?
Oxygen, nitrogen, and carbon dioxide are all classified as pure substances.
Oxygen, nitrogen, and carbon dioxide cannot react with another substance.
Oxygen, nitrogen, and carbon dioxide are chemically bonded to one another.
Oxygen, nitrogen, and carbon dioxide can be classified as elements.

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.