Stanislao Cannizzaro in Italy. He is best known for his contribution to the then-existing debate over atoms, molecules, and atomic weights. He championed Amedeo Avogadro's notion that equal volumes of gas at the same pressure and temperature held equal numbers of molecules or atoms, and the notion that equal volumes of gas could be used to calculate atomic weights. In so doing, Cannizzaro provided a new understanding of chemistry. Stanislao Cannizzaro Stanislao Cannizzaro FRS (13 July 1826 – 10 May 1910) was an Italian chemist. He is remembered today largely for the Cannizzaro reaction and for his influential role in the atomic-weight
Density of air Law). So when water molecules (water vapor) are added to a given volume of air, the dry air molecules must decrease by the same number, to keep the pressure or temperature from increasing. Hence the mass per unit volume of the gas (its density) decreases. The density of humid air may be calculated by treating it as a mixture of ideal gases. In this case, the partial pressure of water vapor is known as the vapor pressure. Using this method, error in the density calculation is less than 0.2% in the range of −10 °C to 50 °C. The density