# How to calculate moles of a gas

Ideal Gas Law Calculator

We start by determining the number of moles of gas present. We know that liters of a gas at STP equals one mole, so: L ? 1mol L = mol. We also know the molecular weight of N 2 (g/mol), so we can then calculate the weight of nitrogen gas in liters: mol ? . First of all, every element has a different molar mass and is expressed as gram per mole. For example, the Chlorine (Cl) has a molar mass of g/mol in the same way Sodium (Na) has a molar mass of g/mol. Moreover, most of the molecules are made up of more than 1 element.

Small gas tanks are often used to supply gases for chemistry reactions. A gas gauge will give some information about how much is in the tank, but quantitative estimates are needed so that the reaction will be able to proceed to completion. Knowing how to calculate the necessary parameters for gases is very helpful to avoid running out earlier than desired.

Molar volume at STP can be used to convert from moles to gas volume and from gas volume to moles. Many metals what is kidney infection symptoms with acids to produce hydrogen gas. How many moles of hydrogen were produced? The volume of gas produced is nearly four times larger than the molar volume.

The fact that the gas is hydrogen plays no role in the calculation. The volume seems correct given the number of moles. If we know the volume of a gas sample at STP, we can determine how much mass is present. What is the mass of the nitrogen gas? We start by determining the number of moles of gas present.

We know that In a multi-step problem, be sure that the units check out. Solution Step 1: List the known quantities and plan the problem. Step 2: Calculate. Summary Conversions between moles and volume of a gas are shown.

Conversions Between Moles and Gas Volume

The ideal gas law is the equation for the state of a hypothetical ideal gas. where P is the pressure in Pascals, V is the volume in m 3, n is the quantity in moles, T is the absolute temperature in Kelvins and finally R is the universal gas constant. At STP of 0°C ( K) and 1 atm, the molar volume of a gas is L/mol. To calculate moles (n) of a gas at STP from its volume (V) in liters, divide the given volume by the molar volume (Vm). Jan 23,  · For this problem, there are 3 moles of gas in the products and 2 moles of gas in the reactants, so the net change in moles of gas is =1 mol.

Easily calculate the pressure, volume, temperature or quantity in moles of a gas using this combined gas law calculator Boyle's law calculator, Charles's law calculator, Avogadro's law calculator and Gay Lussac's law calculator in one. Supports a variety of input metrics such as Celsius, Fahrenheit, Kelvin, Pascals, bars, atmospheres, and volume in both metric and imperial units cubed. This is an ideal gas law calculator which incorporates the Boyle's law , Charles's law, Avogadro's law and Gay Lussac's law into one easy to use tool you can use as a:.

Simply enter the three known measures to calculate the fourth. The calculator uses the combined gas law formula discussed below to perform the computations. It supports both imperial and metric units for volume and pressure and 5 different temperature scales: Kelvin, Celsius, Fahrenheit, Rankine and Reamur, both as input and as output.

The units supported for volume are: mm 3 , cm 3 , m 3 , ml, L litre , gallons, fluid ounces, cubic inches, cubic feet and cubic yards. Units supported for pressure are Pascals, kiloPascals, MegaPascals, GigaPascals, milibars, bars, atmospheres, millimeters of Hg liquid, millimeters of H 2 O liquid, and pound-force per squared inches psi. The gas law calculator uses a combination of several formulas for the behavior of gases which can be derived from four separate gas law formulas and result in the ideal gas formula shown below.

R is equivalent to the Boltzmann constant, but expressed in units of energy per temperature increment per mole the pressure—volume product. In SI based units it is 8. Due to this formula people would often refer to the above tool as a " PV nRT calculator ". A mole is the amount of substance which contains as many elementary entities as there are atoms in 12 g of carbon The ideal gas formula was first stated by the French engineer and physicist Emile Clapeyron in based on four component formulas, discussed below.

With Boyle's law we have that for a constant temperature and gas quantity the pressure of a gas multiplied by its volume is also constant:. This means that under the same temperature, two gases with equal quantity of molecules and equal volume must also have the same pressure, as well as that two gases with equal quantity and pressure must have the same volume. With Charles' law we have that for a constant pressure and gas quantity its volume divided by its temperature is constant:.

With Gay-Lussac's law we have that for a constant volume and gas quantity the pressure of a gas divided by its temperature is a constant:.

Avogadro's law states that if we have constant temperature and pressure the gas volume divided by the gas quantity is a constant. Under these conditions, if two gases have the same volume, they must necessarily contain the same molecular quantities. The combined gas law formula states that with a constant quantity of gas the gas pressure multiplied by its volume and divided by its temperature is also constant:.

The appropriate formula from the ones listed above is chosen automatically when you use this ideal gas law calculator. Understanding when the ideal gas formula applies and when it doesn's is a key prerequisite in making sure you use this ideal gas law calculator accordingly. If a real gas behaves sufficiently like an ideal gas the formula can be used as an approximation depending on the required margin of error. The major issue with the idea gas law is that it neglects both molecular size and inter-molecular attractions, therefore it is most accurate for monatomic gases at high temperatures and low pressures.

With lower densities large volume at low pressure the neglect of molecular size becomes less critical since the average distance between adjacent molecules becomes much larger relative to the size of the molecules themselves. Increasing temperature means higher thermal kinetic energy which diminishes the relative importance of intermolecular attractions. For a more precise equation of state you might want to use the van der Waals equation calculator instead of the ideal gas law calculator above.

Taylor and Ambler Thompson, p. Bureau international des poids et mesures pp. ISBN If you'd like to cite this online calculator resource and information as provided on the page, you can use the following citation: Georgiev G. Calculators Converters Randomizers Articles Search.

Ideal Gas Law Calculator Easily calculate the pressure, volume, temperature or quantity in moles of a gas using this combined gas law calculator Boyle's law calculator, Charles's law calculator, Avogadro's law calculator and Gay Lussac's law calculator in one. Pressure P. Volume V. Moles n. Temperature T. Pressure Unit. Volume Unit. Temperature Unit. Share calculator:. Embed this tool! Related calculators Van der Waals Calculator. About the gas laws calculator This is an ideal gas law calculator which incorporates the Boyle's law , Charles's law, Avogadro's law and Gay Lussac's law into one easy to use tool you can use as a: gas pressure calculator gas volume calculator gas quantity calculator gas temperature calculator Simply enter the three known measures to calculate the fourth.

Gas law formulas The gas law calculator uses a combination of several formulas for the behavior of gases which can be derived from four separate gas law formulas and result in the ideal gas formula shown below. Ideal Gas Law Formula The ideal gas law is the equation for the state of a hypothetical ideal gas. Boyle's Law Formula With Boyle's law we have that for a constant temperature and gas quantity the pressure of a gas multiplied by its volume is also constant: This means that under the same temperature, two gases with equal quantity of molecules and equal volume must also have the same pressure, as well as that two gases with equal quantity and pressure must have the same volume.

Charles's Law Formula With Charles' law we have that for a constant pressure and gas quantity its volume divided by its temperature is constant: Gay-Lussac's Law Formula With Gay-Lussac's law we have that for a constant volume and gas quantity the pressure of a gas divided by its temperature is a constant: Avogadros's Law Formula Avogadro's law states that if we have constant temperature and pressure the gas volume divided by the gas quantity is a constant.

Combined Gas Law Formula The combined gas law formula states that with a constant quantity of gas the gas pressure multiplied by its volume and divided by its temperature is also constant: The appropriate formula from the ones listed above is chosen automatically when you use this ideal gas law calculator. Applicability of the ideal gas formula Understanding when the ideal gas formula applies and when it doesn's is a key prerequisite in making sure you use this ideal gas law calculator accordingly.