Asample of hydrated calcium sulfate has a mass of 2.643 g. after dehydration, the sample has a mass of 2.090 g. what is the percent by mass of water in the hydrate?

2. how is heavy water different from normal water

Ican determine the molar mass of an element by looking on the under the atomic mass for the element. for example the molar mass of phosphorus is 30.974 grams/mole. avogadro’s number tells me the amount of representative particles in 1 mole of any substance. this means 12.011 gram sample of carbon and a 32.0 gram sample of sulfur have the same number of atoms.

What is the most common reason for matter changing its state?