Question

"Under constant conditions of P(pressure) and T(temperature) (and R [gas constant]), write an equation showing d(density) written as a function of M(molecular mass)."

I don't understand this, really! Please help! Thanks in advance!

Answer 1

I'm not sure what you are looking for but here is the general gas law written to include density.
PV = nRT
n = mols = grams/molar mass.
PV = (g/molar mass) RT
P = gRT/(molar mass*V)
density = g/V; therefore,
P = density*RT/molar mass.

Depending upon how I interpret your question your question may be asking for the above equation. However, if I go further, and show P, T, and R as constant, then constant = density/molar mass
If this is not exactly what you want please clarify.

Answer 2

Remember P V = n R T
now n is the number of moles
so n/V = P /R T
that is the number of moles per unit volume
what we want is the mass per unit volume
So multiply both sides by the mass per mole

Answer 3

This is pretty much what I'm looking for! Thanks!