How many pounds of steam equals 1 gallon of water?

Answer 1

Steam is a gas, and is not measured in pounds. It is measured in grams, which measures mass.

To answer your question, 1 gallon of steam (gaseous water) would have the same mass as 1 gallon of water. If you were to change 1 gallon of water to steam, then their mass would remain the same. This is because changes of state are physical changes in science. According to the law of conservation of mass, mass is neither created nor destroyed during physical or chemical changes (because atoms are not lost or gained.) Therefore, the solid form of one substance does not have more mass than the same substance in liquid or gas form, and vice versa.