# AAMC SB C/P 26

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#### PagingDr.F

##### Full Member
7+ Year Member
This is a relatively easy problem to solve but now I'm confused about when to use Avos.#

If it's asking for how many molecules, don't you have to multiply by Avos.#?

lol t-minus 3 days till test and THIS is what I'm confused about...

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Well...all the answers are in mols so...whatever I guess...?

mol is a unit. Like "dozen" actually. How many donuts do you want? Two dozen. How many molecules do you want? 1 mole (of molecules).

and what is the total number of donuts in a dozen? 12 donuts. What is the total number of molecules in a mole? 6.022*10^23 molecules.

I would hope anyone taking the MCAT understand what moles are but thanks lol

I've gotten practice Qs wrong before because I simply forgot to multiply by Avogadro's number but I realized all the answer choices were in moles so clearly I didn't have to (why I answered my own post).

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maybe yall already pointed it out, but the question writer forgot to go that extra step in order to convert to molecules

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and what is the total number of donuts in a dozen? 12 donuts. What is the total number of molecules in a mole? 6.022*10^23 molecules.

I would hope anyone taking the MCAT understand what moles are but thanks lol

Then you still don't understand the question. It's not asking you "what is the total number of molecules in the x mol of ATP that hydrolyzed." It's asking you "what is the total number of ATP molecules that hydrolyzed." So while the total number of donuts in a dozen is indeed 12, when you answer a question asking "what is the total number of donuts consumed?" both "one dozen" and "twelve" are acceptable responses. The question writer didn't miss anything.

both "one dozen" and "twelve" are acceptable responses.

This is true. But if someone asks for total number of molecules you should give an answer in molecules, no? Otherwise, why not just ask "how many moles of atp were hydrolyzed?"

For example, if asked for moles, would it then be okay to give an answer in molecules? By your reasoning it should be because X number of molecules is equivalent to Y number of moles, and both answers are acceptable.

I understand the question and I understand what moles are. I just think they should be more consistent. This is all semantics really...I'll just pay attention to the units used in the answer choices

This is true. But if someone asks for total number of molecules you should give an answer in molecules, no? Otherwise, why not just ask "how many moles of atp were hydrolyzed?"

Not necessarily. If someone asks you how many donuts you want, are you obliged to give the answer in individual donuts? Or can you say "a dozen"? They could ask how many dozen donuts you want. In that case, you would just say "one dozen" or "two dozen" and not "twelve." I'm saying that this question is grammatically consistent with the answer choices.

I argued that it wasn't consistent with other questions I've seen asking specifically for "molecules". See the pictures below for an example.

I've gotten practice Qs wrong before because I simply forgot to multiply by Avogadro's number

My original post indicated I understood what moles are because I was asking about avogadro's number (I.e., 1 mole = 6.022*10^23 molecules/atoms/etc.) Your reply was an explanation of what moles were and somewhat condescending.

For MCAT purposes, when they ask for molecules, they usually imply you must convert moles to molecules. Is it true that you can answer in moles? Yes you can, but it's not what was asked for.

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