A chemical reaction in a bomb calorimeter evolves 3.86 kJ of energy in the form of heat. If the temperature of the bomb calorimeter increases by 4.17 K, what is the heat capacity of the calorimeter?

925.66 J/K

Explanation:

Applying,

Q = CΔt Equation 1

Where Q = amount of heat, C = heat capacity of the calorimeter, Δt = rise in temperature.

make C the subject of the equation

C = Q/Δt Equation 2

From the question,

Given: Q = 3.86 kJ = 3860 J, Δt = 4.17K

Substitute into equation 2

C = 3860/4.17

C = 925.66 J/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%