Question

26. На примусе нагрели 2 л воды от 12 до 100 °С. При этом сгорело 50 г керосина. Какое количество теплоты по- лучила вода и сколько его выделилось при сгорании ке- росина? Почему не равны друг другу эти количества те- плоты? Какую часть составляет количество теплоты, использованное на нагревание воды, от количества те- плоты, выделившегося при сгорании керосина?​

Answer 1

Объяснение:

Масса воды: 2 кг.

По формуле cm(t-t0) находим теплоту, потраченную на нагрев воды. Это 739.200 Дж.

Найдём теплоту, выделенную при сгорания керосина: это масса помноженная на удельную теплоту сгорания керосина.

0.05кг × 40.800.000 Дж/кг = 2.040.000 Дж.

Количества теплоты не равны, так как некоторое количество теплоты уходило в окружающую среду.

$\frac{739200}{2040000} = 0.36$

Но это значение округленное, имейте в виду.

Answer 2

Calculation of Heat Received by Water and Heat Released by Kerosene

To calculate the heat received by the water and the heat released by the kerosene, we can use the formula:

Q = mcΔT

Where: - Q is the heat energy (in joules) - m is the mass of the substance (in grams) - c is the specific heat capacity of the substance (in J/g°C) - ΔT is the change in temperature (in °C)

In this case, we have: - Mass of water (m1) = 2000 grams (2 liters of water, assuming the density of water is 1 g/mL) - Initial temperature of water (T1) = 12°C - Final temperature of water (T2) = 100°C - Mass of kerosene (m2) = 50 grams

Let's calculate the heat received by the water and the heat released by the kerosene.

Heat Received by Water

The specific heat capacity of water is approximately 4.18 J/g°C [[1]]. Using the formula mentioned above, we can calculate the heat received by the water:

Q1 = m1c1ΔT1

Q1 = 2000g × 4.18 J/g°C × (100°C - 12°C)

Calculating this, we find that the heat received by the water is approximately 313,760 J.

Heat Released by Kerosene

To calculate the heat released by the kerosene, we need to know the specific heat capacity of kerosene. Unfortunately, the specific heat capacity of kerosene is not readily available in the search results. However, we can assume that the specific heat capacity of kerosene is similar to that of other hydrocarbons, which is around 2.2 J/g°C [[2]].

Using the formula mentioned earlier, we can calculate the heat released by the kerosene:

Q2 = m2c2ΔT2

Q2 = 50g × 2.2 J/g°C × (100°C - 12°C)

Calculating this, we find that the heat released by the kerosene is approximately 8,360 J.

Difference in Heat Quantities

The heat received by the water (313,760 J) and the heat released by the kerosene (8,360 J) are not equal. This difference is due to the different specific heat capacities of water and kerosene. Water has a higher specific heat capacity compared to kerosene, which means it requires more heat energy to raise its temperature by the same amount.

Proportion of Heat Used for Heating Water

To determine the proportion of heat used for heating the water compared to the heat released by the kerosene, we can calculate the ratio of the heat received by the water (Q1) to the total heat released (Q1 + Q2):

Proportion = Q1 / (Q1 + Q2)

Proportion = 313,760 J / (313,760 J + 8,360 J)

Calculating this, we find that the proportion of heat used for heating the water is approximately 97.4%.

Therefore, the heat used for heating the water accounts for approximately 97.4% of the total heat released by the kerosene.

I hope this helps! Let me know if you have any further questions.