Question

A sample of O2 gas at a given temperature and pressure has a density of 1.30 g L–1 . What is the density of gaseous propane (C3H8) under the same conditions?

Answer 1

The density of gaseous propane (C3H8) under the same conditions of temperature and pressure as O2 gas is 0.945 g/L.

Step-by-step explanation:

The density of a gas is determined by its mass and volume. In this question, the density of O2 gas is given as 1.30 g L–1. To find the density of gaseous propane (C3H8) under the same conditions, we need to use the ideal gas law equation: PV = nRT. This equation relates pressure (P), volume (V), number of moles (n), gas constant (R), and temperature (T).

Since the pressure and temperature are given to be the same for both gases, we can compare the densities using the ratio of the number of moles to volume. The molar mass of O2 is 32 g/mol, while the molar mass of C3H8 is 44 g/mol. Therefore, the density of gaseous propane under the same conditions would be:

(1.30 g/L × 32 g/mol) / 44 g/mol = 0.945 g/L

Answer 2

Density is a value for mass, such as kg, divided by a value for volume, such as m3. Density is a physical property of a substance that represents the mass of that substance per unit volume. For gases we use the ideal gas equation to solve for density. We do as follows:

PV = nRT
PV = mRT / MM
Density = m/V = PMM / RT

From the conditions given of the O2 system we can determine P/RT as follows:

P/RT = density / MM = 1.30 / 32
P/RT = 0.0406

density of propane = 0.0406 x 44.11 = 1.79 g/L