Answer:
The net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide is -470.4 kJ/mol.
Explanation:
Step 1 : Calcium carbide and water react to form acetylene and calcium hydroxide

..[1]
Step 2 : Acetylene, carbon dioxide and water react to form acrylic acid
..[2]
Using Hess's law:
[1] × 6 + [2]



The energy released on formation of 5 moles of acrylic acid = -2352 kJ
The energy released on formation of 1 moles of acrylic acid :

Hence, the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide is -470.4 kJ/mol.
There are several units for expressing energy, Most common are joules and kilocalories.
The conversion factor of joule to kilocalories is
1 kilo calorie = 4184 J
∴ x kilo calorie = 256 J
x =

kilo calories
Thus, 256 J = 0.0611 kilocalories
It's because of Avagadro's number.
- It is known as Avagadro's constant too.
- It states that at constant temperature one mole of any substance contain same number of atoms i.e n no of atoms
where
