<u>Answer:</u> The amount of heat released is 155.9 kJ
<u>Explanation:</u>
To calculate the number of moles, we use the equation:

We are given:
Given mass of HF = 100.0 g
Molar mass of HF = 20 g/mol
Putting values in above equation, we get:

To calculate the heat of the reaction, we use the equation:

where,
= amount of heat released =
n = number of moles = 5 moles
= enthalpy change of the reaction = 31.18 kJ/mol
Putting values in above equation, we get:

Hence, the amount of heat released is 155.9 kJ