Determine the enthalpy for this reaction: Ca(OH)2(s) CO2(g)→CaCO3(s) H2O(l).

  This is an acid-base reaction (neutralization): Ca(OH) 2 is a base, CO 2 is an acid. ; White, odorless powder. [Note: Readily absorbs CO2 from the air to form calcium carbonate.]

Explanation:

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%