Question

Определите энергию, необходимую для превращения 2 кг льда при температуре 0ºC в воду с температурой 40ºC. Удельная теплота плавления льда 3,4·10³ Дж/кг, удельная теплоемкость воды 4200 Дж/(кг·ºC) .

Answer 1

3400*2+2*40*4200=6800+480000=486800 Дж

Answer 2

Calculation of Energy Required to Convert Ice to Water

To determine the energy required to convert 2 kg of ice at 0ºC to water at 40ºC, we need to consider two processes: the phase change from solid to liquid and the heating of the liquid water to the desired temperature.

1. Phase Change from Ice to Water: - The specific latent heat of fusion, also known as the specific heat of melting or the specific heat of fusion, is the amount of energy required to change the phase of a substance from solid to liquid at a constant temperature. - The specific latent heat of fusion for ice is given as 3.4 × 10³ J/kg. - Since we have 2 kg of ice, the energy required for the phase change is: Energy for phase change = mass × specific latent heat of fusion Energy for phase change = 2 kg × 3.4 × 10³ J/kg

2. Heating the Liquid Water: - Once the ice has melted into water, we need to heat the water from 0ºC to 40ºC. - The specific heat capacity of water is the amount of energy required to raise the temperature of 1 kg of water by 1ºC. - The specific heat capacity of water is given as 4200 J/(kg·ºC). - Since we have 2 kg of water, the energy required to heat the water is: Energy for heating = mass × specific heat capacity × temperature change Energy for heating = 2 kg × 4200 J/(kg·ºC) × (40ºC - 0ºC)

3. Total Energy Required: - To find the total energy required, we need to sum up the energy for the phase change and the energy for heating the water: Total energy required = Energy for phase change + Energy for heating

Let's calculate the total energy required:

Energy for phase change = 2 kg × 3.4 × 10³ J/kg

Energy for heating = 2 kg × 4200 J/(kg·ºC) × (40ºC - 0ºC)

Total energy required = Energy for phase change + Energy for heating

Please note that the specific heat capacity and specific latent heat of fusion values used in this calculation are approximate and may vary slightly depending on the source.