What is the mass of water that can be heated from 25 to 80 degrees, transferring to it all the energy

What is the mass of water that can be heated from 25 to 80 degrees, transferring to it all the energy released during the complete combustion of 2.1 kg of anthracite?

To determine the value of the mass of heated water, we will use the equality: ma * qa = Sv * mw * (t – t0), whence we express: mw = ma * qa / (Sv * (t – t0)).

Constants and variables: ma – mass of spent anthracite (mа = 2.1 kg); qа – specific heat of combustion of anthracite (qа = 3 * 10 ^ 7 J / kg); Sv – specific heat capacity of water (Sv = 4200 J / (kg * ºС)); t is the temperature reached by the water (t = 80 ºС); t – temperature before heating (t = 25 ºС).

Calculation: mv = ma * qa / (Sv * (t – t0)) = 2.1 * 3 * 10 ^ 7 / (4200 * (80 – 25)) = 272.7 kg.

Answer: Due to 2.1 kg of anthracite, 272.7 kg of water is heated.