You are conducting a calorimetry experiment using a calorimeter with 500mL of water in its outer chamber to determine the enthalpy of reaction of a chemical reaction. The initial temperature of the water is 25°C. After the reaction, the temperature of the water is 62.8°C. Disregarding any heat loss to the walls of the container, calculate the ΔHr0. The specific heat of water is 4.18J/(g•K).

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%