How much water can be heated from 10 ° C to 60 ° C with full energy consumption from burning 50 g of alcohol?

How much water can be heated from 10 ° C to 60 ° C with full energy consumption from burning 50 g of alcohol? The specific heat of combustion of alcohol is 26 MJ / kg; the specific heat of water is 4200 J / kg ° C.

Let’s calculate the amount of heat that will be released during the complete combustion of alcohol:

26 MJ / kg = 26,000,000 J / kg;

50 g = 0.05 kg;

Q = Qcombustion (alcohol) * m (alcohol) = 26,000,000 * 0.05 = 1,300,000 J;

Let’s calculate the mass of water that can be heated with this amount of heat:

ΔТ = Т2 – Т1 = 60 – 10 = 50 ° С;

m (H2O) = Q / (Sud (H2O) * ΔT) = 1,300,000 / (4200 * 50) = 6.19 kg.

Answer: m (H2O) = 6.19 kg.