Problema 1 · Química II URV 2000

Problema 1. Combustión de antracita para calentar agua

During the combustion of 1 kg of anthracite coal, an energy of approximately 7300 kcal is released. Assuming that the whole amount of released heat is completely transferred to the system, determine what mass of coal (in grams or kilograms) is needed to heat 4.0 kg of water from room temperature (20 °C) up to its boiling point (100 °C) at an atmospheric pressure of 1 atm.

Data:

Specific heat capacity of liquid water, $c_e(\mathrm{H_2O}) = 4.18\ \mathrm{J\cdot g^{-1}\cdot{^\circ}C^{-1}}$; $1\ \mathrm{cal} = 4.184\ \mathrm{J}$ (take $4.18\ \mathrm{J/cal}$).