Question

The amount of energy released in burning $1kg$ of coal is

• A. $3MJ$
• B. $30MJ$
• C. $300MJ$
• D. $3000MJ$

Answer 1

Answer: (B)

$30MJ$

When $1kg$ of coal is burnt the energy released is $30MJ(=3\times {10}^{7}J)$.With a complete combustion or fission, approx. 8 kWh of heat can be generated from 1 kg of coal, approx. 12 kWh from 1 kg of mineral oil and around 24,000,000 kWh from 1 kg of uranium-235. Related to one kilogram, uranium-235 contains two to three million times the energy equivalent of oil or coal.