Mendeleev · Science

Ideal gases: linking pressure, volume and temperature

The ideal-gas model links pressure, volume, amount of substance and temperature through PV = nRT. It is powerful, but real gases deviate especially at high pressure and low temperature.

Core idea

The ideal-gas model links pressure, volume, amount of substance and temperature through PV = nRT. It is powerful, but real gases deviate especially at high pressure and low temperature.

A concrete example

If the amount of gas stays fixed and temperature rises in a rigid container, pressure rises within the ideal model.

Why it matters

This concept connects symbolic scientific language with what actually happens at atomic, molecular or experimental scales. Before applying a formula, always check the quantities, units and assumptions of the model.

Check it yourself

Restate the idea without technical vocabulary, then repeat the reasoning with a simple value. If your explanation and calculation tell different stories, revisit the assumptions.

If the amount of gas stays fixed and temperature rises in a rigid container, pressure rises within the ideal model.

Understand it before converting

Volume is not just a classroom quantity: it appears constantly in cooking, chemistry, pharmacy, fuels and construction. Units are chosen for practical reasons. Some are convenient in everyday life, while others dominate scientific or technical work. This page deliberately focuses on familiar units — millilitres, litres, cubic centimetres, cubic metres and US gallons — instead of presenting a long catalogue of rarely used formats. Every pair links to a dedicated conversion page with the calculation rule, worked examples and useful reference values. The aim is to get the answer quickly while still understanding what is being converted and whether the result makes physical sense.

Volume