Help. Please. Chemistry question. It's so simple. Please help. (1 Viewer)

[Bendwhat?_over]

View attachment 46859

How do I do this

 

[cheesynooby]

multiply by avogadro's constant?

u could think of the mass as being in g/molecule
so to get to RMM (in g/mol) multiply by molecules/mol so the molecules cancel
and molecules/mol is avogadro's constant i.e. there are ~6.02*10^23 molecules in one mole of those molecules

 

[Bendwhat?_over]

So it's 9.30x10^-23 * 6.022x10^23 ? Which is ~56? So it's Fe?

 

[cheesynooby]

yeaa but you cant know what molecule it is only the molar mass, since a lot of molecules have a molar mass of around 56

 

[Bendwhat?_over]

Alright... Thank you, much obliged!!!

 

[wizzkids]

The data gives the mass of three different molecules
Your task is to figure out what would be the mass of 1 Mole of each of these three molecules.
The answers are X=56 g/mol, Q= 107.8 g/mol and Z=254 g/mol. That is all you can determine from the data. You can't work out empirical formulae or anything else like that.
The question is asking for the "relative molecular mass" which is a bit weird. Q is about double the molecular mass of X, and Z is about 4.5 times the molecular mass of X.

 

[cheesynooby]

The data gives the mass of three different molecules
Your task is to figure out what would be the mass of 1 Mole of each of these three molecules.
The answers are X=56 g/mol, Q= 107.8 g/mol and Z=254 g/mol. That is all you can determine from the data. You can't work out empirical formulae or anything else like that.
The question is asking for the "relative molecular mass" which is a bit weird. Q is about double the molecular mass of X, and Z is about 4.5 times the molecular mass of X.

i thought relative molecular mass is basically equivalent to molar mass and the "relative" means each unit is 1/12 of carbon-12's mass

 

[wizzkids]

i thought relative molecular mass is basically equivalent to molar mass and the "relative" means each unit is 1/12 of carbon-12's mass

Yes, that's true. That is valid interpretation of the use of the term "relative". Relative to C-12.