A5.49g sample of iron(iii) chloride hydrate was found to contain 2.20g of water. what is the complete formula of the hydrate?

We are given the mass of the hydrate and the mass of the water present. In this case, the mass of anhydrous iron iii chloride is equal to 3.29 grams. This means the mass percent of anhydrous part is 60 percent. The mass ratio of anhydrous to hydrate is equal to 162.2 g / x where x is the molar mass of the hydrate. x then is equal to 270. 66 g/mol. Hence the total molar mass of water is equal to 108. 46 g/mol equal to about 6 moles of H20. The molecular formula hence is FeCl3 - 6H2O

Heat is involved in chemical change in two ways; chemical changes either result in heat being added to or removed from an object, and chemical changes require a certain amount of heat before they can take place.