Grade 11 Chemistry question.

I've been trying to answer this for the past 2 days. I am stumped.


combine the ideal gas law (PV=nRT) nad the mass to moles conversion (n= m/MM) to solve for the experimental molar mass.

I have the following information:
mass
volume
pressure
temperature

how would I find the molar mass? I tried it a few diffrent ways, but I always end up really low. it should end up being around 58. but i have no idea how...

OK - first you need to solve for moles:

n = PV/RT

with P, V and T given (and R being the gas constant), you can solve for n

Now the molecular mass is the number of grams divided by the number of moles (g/mol). Or, MM = m/n.

Without other information (like the values), I cannot confirm your number but....
you really need to be careful with units in the gas law. Your value of R should be in the same units that are used for P (atm or torr), V (L, not mL) and T (in degrees K, not degrees C)

Hope this helps

PV=nRT

PV=(m/MM)RT

pressure * volume = (mass/x) * idealgasconstant * temperature

solve for x

You would have to substitute m/MM for n in the other equation.

PV=(m/MM)RT

Try that.