How many kilojoules of energy are necessary to raise the temperature of 3 kilograms of cast iron from 30 degrees celsius to 120 degrees celsius?

Specific heat of cast iron is 0.46 kJ / kg K.

Energy change = 0.46 kJ / kg K * 3 kg * (120 - 30) K = 124.2 kJ

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

frequency, z, and the collision density, z, in carbon dioxide (co2), r 180 pm at 30 °c and 120 kpa