Question on mass @ STP

[Cesar7d7]

Good Morning all! I have a question that I believe I'm right but the answer key says I'm wrong, lol!

Which of the following has the greatest mass at STP?

A. 0.5L of Ne atoms
B. 1L of H2O as a gas
C. 0.5L of Me-OH as a gas
D. 1L of D2O as a gas

The "answer" is C however I keep coming up with D as the answer. I can't seem to get my calculations to align with C as the answer. I honestly think that it's a typo or something but I have no way to be sure.

Can someone help me shed some light on this question???

Please and thank you.

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[basophilic]

I picked D as well; I'm assuming your reasoning, like mine, is that the mass depends entirely on product of molecular mass and volume (since pressure and temperature are constant, but you can't assume volume to be constant)
I don't see a logical reason for C over D; what's their reasoning for C?

 

[Cesar7d7]

Yep, same reasoning. Unfortunately the answer key does not give a rationale just a question number and a letter...Fun times!

 

[chemist16]

I did it and I'm also getting D. The key point is that the relative masses (which is the important point here, not the absolute masses) are in fact dependent on molar mass and volume. I think that whatever book you're using got their relative mass and absolute mass confused.

 

[chemtopper]

I am also getting D and it is the right answer ...may be some error in the book ....

 

[RaspberrySlushy]

D as well here.

 

[shefv]

D

I wasn't sure about what molar mass to use for Me though (not on periodic table)

 

[chemtopper]

D

I wasn't sure about what molar mass to use for Me though (not on periodic table)

Me is the methyl group-CH3