Volumetric vs molar flow rate of gases

One of the biggest misconceptions I see is people mistaking molar flow rates for volumetric flow rates. For example, say we have a flow rate of $10\ Nm^3/s$. This is not the same as a flow rate of $10\ m^3/s$. The first is a molar flow rate, whereas the second is a volumetric flow rate. To see why, let's make some definitions. The volumetric flow rate of a fluid is related to the molar flow rate by:

$$Q=\frac{nMr}{\rho}$$

Where $\rho$ is the fluid density, $n$ is the molar flow rate, and $Mr$ is the fluid's molar mass.
Incompressible fluids (most liquids) have constant density; however, for compressible fluids (gases), the density depends on the pressure and temperature. For an ideal gas, the relationship is the well-known ideal gas law:

$$PV=nRT$$

or

$$PV=(m/Mr)RT$$

Which can be rearranged to give density:

$$\rho = \frac{PMr}{RT}$$

Substituting this into the molar flow rate equation:

$$Q=nMr\frac{RT}{PMr}$$

Simplifying down to:

$$Q=\frac{nRT}{P}$$

Notice the above equation is independent of $Mr$ and is therefore independent of the fluid composition. That means this equation holds for any gas. Now back to what the $N$ in front of $Nm^3/s$ means. This refers to the normal conditions defined as $T=273.15 K$ and $P = 101325 Pa$.

Now, looking back at the equation we defined, if $P$, $R$ and $T$ are constant, then we have: $Q=0.0224n$. In other words, the volumetric flow rate defined at a set of standard conditions is equivalent to a molar flow rate.