Created By : Rina Nayak

Reviewed By : Rajashekhar Valipishetty

Last Updated : May 01, 2023


The online STP calculator tool speeds up the process by displaying the density of a gas in a fraction of a second. Simply type in the necessary values and then tap on the calculate button to avail the density of gas at STP.

What is STP in Density?

The Greek letter rho (ρ)  is used to represent it. The density of air, or how light it is, is determined by the air's temperature and pressure. The density of air is usually expressed in STP units (standard temperature and pressure). At 0 degrees Celsius, STP is one atmosphere of pressure.

How do I Estimate Gas Densities at STP?

Density is defined as the ratio of mass to volume. You must determine the mass of a sample of unit volume in order to solve the problem. Here's a general strategy for estimating gas densities quickly and cheaply:

Calculate the molar volume. One mole of an ideal gas will take up 22.414 L at STP. The molar volume of an ideal gas is V/n = RT/P at other temperatures and pressures. If the gas isn't ideal, you'll have to look up the molar volume in a handbook or use a real-gas equation of state to find it out.

Density is defined as the ratio of mass to volume, so the density is calculated by dividing the molar mass by the molar volume. At room temperature and pressure, gas densities are around 1 g/L, or about 1/1000th the density of liquids.

It's worth noting that you can quickly determine which gas is the densest. If they behave perfectly, they will all have the same molar volume at STP, with the densest gas having the highest molar mass.

Density at STP Formula

The formula to calculate Density at STP is given by D = M/V

  • Where, M =  Molar mass
  • V = Volume of a gas

FAQs on Density at STP Calculator

1. At STP, how do you calculate the density of a gas?

A gas's density at STP. At STP, the formula D= M/V is used, where M is the molar mass and V is the molar volume of a gas (22.4 liter/mole).


2. Is the density of gases the same at STP?

All ideal gases have the same number density, they all have the same molar volume. This will be 22.4 liters at STP. This is useful for visualizing the distance between molecules in various samples. For example, A sample of liquid water has a mass density of 1 g mL-1.


3. At STP, which has a higher density: hydrogen or helium?

Hydrogen has a mass of 1.001 g/mole, while Helium has a mass of 4.002 g/mole. As a result, dividing the mass of one mole of an element by the volume of one mole of the gas at STP yields the density of each gas. Helium has a density of more than four times that of hydrogen.


4. What is the ammonia gas density at STP?

The ammonia gas density at STP is 0.761g/L.


5. What is the STP volume?

Standard temperature and pressure (STP) is a good set of conditions to use when comparing other gas properties. Gases have a volume of 22.4 L per mole at STP. The ideal gas law can be used to calculate gas densities.