What amount of heat must be spent in order to obtain steam from 5 kg ice at a given temperature (-10 s)

| March 28, 2021 | education

What amount of heat must be spent in order to obtain steam from 5 kg ice at a given temperature (-10 s) at 100 s? The specific heat capacity of ice is 2100 J / (kg ° C), its melting temperature is 0 ° C, the specific heat of ice melting is 340 kJ / kg, the specific heat capacity of water is 4200 J / (kr s), the boiling point of water is 100 C, and the specific heat of vaporization of water is 2, 3 MJ / kg.

Data: m = 5 kg; t = -10 ºС.

Constants: C1 = 2100 J / (kg * ºС); λ = 340 * 10 ^ 3 J / kg; tmelt = 0 ºС; C2 = 4200 J / (kg * ºС); tк = 100 ºС; L = 2.3 * 10 ^ 6 J / kg.

1) Heating: Q1 = C1 * m * (tmelt – t) = 2100 * 5 * (0 – (-10)) = 105000 J.

2) Melting ice: Q2 = λ * m = 340 * 10 ^ 3 * 5 = 1700 * 10 ^ 3 J.

3) Heating to boiling: Q3 = C2 * m * (tc – tmelt) = 4200 * 5 * (100 – 0) = 2100000 J.

4) Vaporization: Q4 = L * m = 2.3 * 10 ^ 6 * 5 = 11.5 * 10 ^ 6 J

4) Q = 105000 + 1700 * 10 ^ 3 + 2100000 + 11.5 * 10 ^ 6 ≈ 15.4 MJ.



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