Question

The heat of polymerization of ethylene is 25 Kcal/mol. The amount of heat generated during the polymerization of 5.6 kg polyethylene is ............ Kcal. {(Round off to the nearest integer)}

Hint:

The heat of polymerization is per mole of monomer. Always convert the mass to moles using the molar mass before multiplying by heat of reaction.

Answer 1

We are given:
- Heat of polymerization = \( 25 \, {Kcal/mol} \)
- Mass of polyethylene = \( 5.6 \, {kg} = 5600 \, {g} \)
- Molar mass of polyethylene (monomer unit ethylene) = \( 28 \, {g/mol} \)
To find the total number of moles of ethylene polymerized: \[ {Moles of ethylene} = \frac{5600 \, {g}}{28 \, {g/mol}} = 200 \, {mol} \] Now calculate the total heat released: \[ {Heat} = 200 \, {mol} \times 25 \, {Kcal/mol} = 5000 \, {Kcal} \]