Answer:
ΔH = -59.6kJ/mol
Explanation:
The reaction that occurs between Ag⁺ and Cl⁻ ions is:
Ag⁺ + Cl⁻ → AgCl(s) + ΔH
To find ΔH we need to obtain moles of reaction and heat released in the reaction because ΔH is defined as heat released per mole of reaction.
Moles of reaction:
Moles of Ag⁺ and Cl⁻ added are:
Ag⁺: 0.100L * (0.100mol / L) = 0.01moles
Cl⁻: 0.100L * (0.200mol / L) 0 0.02 moles
That means limiting reactant is Ag⁺ and moles of reaction are 0.01 moles
Heat released:
To find heat released we must use coffe cup calorimeter equation:
Q = C*m*ΔT
Where C is specific heat of solution (4.18J/g°C), m is the mass of solution (200g because there are 100 + 100mL = 200mL and density of solution is 1g/mL) and ΔT is change in temperature (25.30°C - 24.60°C = 0.70°C).
Replacing:
Q = C*m*ΔT
Q = 4.18J/g°C * 200g * 0.70°C
Q = 585,2J
Is total heat released.
The calorimeter absorbs:
15.5J / °C * 0.7°C = 10.85
Thus, when 0.01 moles reacts, 585.2J + 10.85 = 596.05J are released (Heat released is heat abosrbed by calorimeter + Heat absorbed by water) and ΔH is:
ΔH = 596.05J / 0.01 moles =
ΔH = 59605J / mol =
As heat is released, ΔH < 0.
