Based on the reactivities of the elements involved, which reaction will form products that are more stable than the reactants? O A 2A1Brz + 32n + 3ZnBr2 + 2A
OB. CaBr2 + 2Na + 2NaBr + Ca
OC. MgBr2 + H2 + 2HBr + Mg
OD. BaBr2 + Ca - CaBr2 + Ba
OE 2LIBr+ Ba - BaBrą + 2L1

it is a good conductor

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%