Physics
jackie98227
40

A student tests the acidity of nitric acid (HNO3) by dissolving a sample of HNO3 in a solution of liquid methane. He then uses an electronic tool to measure the solution and determines that it is highly acidic. What is wrong with the student’s experiment?

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(1) Answers
albertotorres80

Sorry I didn't see this before... Okay, I see two major problems with this student's experiment: 1) Nitric acid Won't Dissolve in Methane Nitric acid is what's called a mineral acid. That means it is inorganic (it doesn't contain carbon) and dissolves in water. Methane is an organic molecule (it contains carbon). It literally cannot dissolve nitric acid. Here's why: For nitric acid (HNO3) to dissolve into a solvent, that solvent must be polar. It must have a charge to pull the positively charged Hydrogen off of the Oxygen. Methane has no charge, since its carbon and hydrogens have nearly perfect covalent bonds. Thus it cannot dissolve nitric acid. There will be no solution. That leads to the next problem: 2) He's Not actually Measuring a Solution He's picking up the pH of the pure nitric acid. Since it didn't dissolve, what's left isn't a solution—it's like mixing oil and water. He has groups of methane and groups of nitric acid. Since methane is perfectly neutral (neither acid nor base), the electronic instrument is only picking up the extremely acidic nitric acid. There's no point to what he's doing. Does that help?

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