A gaseous compound containing carbon and hydrogen was analyzed and found to consist of between 80 and 90 percent carbon by mass. At 145ºC and 1.00 atm, the density of this compound is 2.45 g/L. What is the molar mass of the compound?

Question

Quizplus · Accepted Answer

The molar mass of the compound can be calculated using the ideal gas law equation rearranged to solve for molar mass (M): $M = \frac{dRT}{P}$, where $d$ is the density of the gas, $R$ is the ideal gas constant (0.0821 L·atm/K·mol), $T$ is the temperature in Kelvin, and $P$ is the pressure in atm. Given that the density ($d$) is 2.45 g/L, the temperature ($T$) is 145ºC (which is 418 K when converted to Kelvin), and the pressure ($P$) is 1.00 atm, substituting these values into the equation gives: $M = \frac{(2.45 g/L) \times (0.0821 L·atm/K·mol) \times (418 K)}{1.00 atm} = 84.2 g/mol$.

A Gaseous Compound Containing Carbon and Hydrogen Was Analyzed and Found