<u>Answer:</u> The enthalpy change of the unknown solid is 3.824 kJ/mol
<u>Explanation:</u>
To calculate the mass of solution , we use the equation:
Density of solution = 1.20 g/mL
Volume of solution = 150.0 mL
Putting values in above equation, we get:
The equation used to calculate heat released or absorbed follows:
q = heat absorbed or released
m = mass of solution = 180 g
c = specific heat capacity = 4.18 J/g°C
= change in temperature = 16.01°C
Putting values in above equation:
To calculate the enthalpy change of the reaction, we use the equation
where,
q = amount of heat absorbed = 12.046 kJ
n = number of moles of solid = 3.15 moles
= enthalpy change of the reaction
Putting values in above equation, we get:
Hence, the enthalpy change of the unknown solid is 3.824 kJ/mol