Ideal Gas Law
Calculator
Results
- Amount of substance (mol)
- 1.000001
- Number of particles
- 6.0221489425850376e+23
Chemistry results
| Amount of substance (mol) | 1.000001 |
| Number of particles | 6.0221489425850376e+23 |
formula-map diagram
- Amount of substance (mol)
- 1.000001
- Number of particles
- 6.0221489425850376e+23
Formula breakdown
Formula
n = (P × V) ÷ (R × T)= 1.0000013587502
Note
Simplified model: these results assume ideal behaviour (ideal gases, dilute solutions, complete reactions) and standard textbook constants. Real laboratory values vary with temperature, pressure, purity and activity coefficients. Do not rely on this for safety-critical or analytical work.
More in Chemistry
See all →Frequently asked questions
What do P, V, n, R and T represent in PV = nRT?+
P is pressure, V is volume, n is the number of moles of gas, T is absolute temperature in kelvin, and R is the universal gas constant (0.0821 L·atm/(mol·K), or 8.314 J/(mol·K) in SI units). The equation links these four measurable properties of an ideal gas.
Why must temperature be in kelvin and not Celsius?+
The ideal gas law assumes temperature is measured from absolute zero, so using Celsius (which can be zero or negative) would make the pressure-volume relationship physically meaningless. Always convert with K = °C + 273.15 before plugging into the formula.
How accurate is the ideal gas law for real gases?+
It's a good approximation at low pressure and high temperature, where gas molecules are far apart and intermolecular forces are negligible. At high pressure or low temperature, real gases deviate noticeably and a correction like the Van der Waals equation is more accurate.
Which value of R should I use?+
Use R = 0.0821 L·atm/(mol·K) when pressure is in atmospheres and volume in liters, or R = 8.314 J/(mol·K) when working in SI units (pascals and cubic meters). Using the wrong R for your unit system is the most common source of error with this law.
Can I use the ideal gas law to find the number of moles of an unknown gas sample?+
Yes — if you measure P, V and T for a gas sample, rearranging to n = PV / (RT) gives the moles directly, which is a standard way to determine molar mass when combined with a measured mass.