Knowing that the combustion of 30.0 ml of kerosene produces enough heat to heat and melt 10.0 kg
January 2, 2021 | education
| Knowing that the combustion of 30.0 ml of kerosene produces enough heat to heat and melt 10.0 kg of silver, determine the initial temperature of silver.
Q1 = Q2 + Q3.
Q1 (kerosene combustion) = q * m1, where q = 4.6 * 107 J / kg), m1 = ρ * V (ρ = 800 kg / m3, V = 30 ml = 30 * 10-6 m3).
Q2 (silver melting) = λ * m2, where λ = 0.87 * 105 J / (kg * K), m2 = 10 kg.
Q3 (heating silver) = С * m2 * (tmelt – tn), where С = 250 J / (kg * K), tm = 962 ºС).
q * m1 = λ * m2 + С * m2 * (tpl – tn).
4.6 * 107 * 800 * 30 * 10-6 = 0.87 * 105 * 10 + 250 * 10 * (962 – tn).
250 * 10 * (962 – tн) = 234000.
962 – tn = 93.6.
tн = 868.4 ºС.
Answer: The initial temperature is 868.4 ºС.
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