Answer:
Enthalpy change for the dissolution of the unknown solid = 4.6 Kj/mole
Explanation:
Using Q = m x Cs x ΔT ................................(1)
where Q = Amount of heat absorbed
m = Mass of solution
Cs = Specific heat capacity of solution
ΔT = Change in temperature
Given Density of solution = 1.20 g/ml
And volume of solution = 150 ml
Mass of solution = density x volume
= 1.2 x 150
= 180 g
From equation (1)
Q = 180 x 4.18 x 19.2 = 14446.08 = 14.4 Kj
So, ΔH of the dissolution of the unknown solid = =
= 4.6 kj/mole