However, the density does not change. This is because the mass and volume increase at the same rate/proportion! Even though there is more molasses (mass) in test tube A, the molasses also takes up more space (volume).

For liquids, temperature is an important factor that can affect a liquids density. Therefore we generally will always describe density at a given temperature for comparison purposes. In general, as liquid temperature increases, density decreases.

This means that the density of a substance, for example iron, does not change by much when it melts. Relative particle density for a solid, liquid and gas. When a liquid changes into a gas, the spacing between the particles increases significantly.

If the mass of the object stays the same but the volume of the object decreases then its density becomes greater. If the volume of the object stays the same but the mass of the object increases then its density becomes greater.

There is a clear relationship between mass, density and volume. Unlike mass and volume, increasing the amount of material measured does not increase or decrease density. However, since volume deviates with changes in temperature and pressure, density can also change with temperature and pressure.

Molar Mass of Gases and Gas Mixtures The molar volumes of all gases are the same when measured at the same temperature and pressure (22.4 L at STP), but the molar masses of different gases will almost always vary.

Density of a gas with a constant number of molecules in a constant volume, varies according to the molecular weight. The higher the molecular weight the higher the density.

When a liquid or gas is heated, the molecules move faster, bump into each other, and spread apart. Because the molecules are spread apart, they take up more space. The molecules move more slowly and take up less space. Therefore temperature can affect density.

Gas densities are somewhere around 1 g/L at room temperature and pressure- about 1/1000th the density of liquids. Note that you can very quickly decide which gas is going to be densest. If they behave ideally, all have the same molar volume at STP and the densest gas will be the one with the highest molar mass.

Neon

CH4

helium

Radon

copper

Uses of STP Standard reference conditions are important for expressions of fluid flow rate and the volumes of liquids and gases, which are highly dependent on temperature and pressure. STP commonly is used when standard state conditions are applied to calculations.

Standard Temperature and Pressure (STP) is defined as 0 degrees Celsius and 1 atmosphere of pressure.