What is the molar mass of an unknown hydrocarbon whose density is measured to be 1.97 g/l at stp?

  The correct answer is :  44.1  g / mol

Explanation:    d  =  PM / RT

                         M  =  dRT / P

d = 1.97 g / l

R = ideal gas (0.082 06 l - atm / mol - ° K)

P = 1 atm

T = 273 ° K

M = Molar mass

M = 1.97 g / l  x  0.082 l - atm / mol - ° K   x  273 ° K / 1 atm

M =  44.1 g / mol

The correct answer is

M = 44.1 g / mol

Explanation:

Hello!

Let's solve this!

First we write down the data

d: 1.97 g / L

P: 1 atm

R: 0.082 atmL / Kmol

T: 273K

From the ideal gas formula:

d = P * M / R * T

We cleared M to know the molar mass.

M = (d * R * T) / P

M = (1.97 g / L * 0.082 atmL / Kmol * 273K) / 1atm

The correct answer is

M = 44.1 g / mol