Question

У залізній коробці масою 250 г міститься 150 г олова за кімнатної температури. Яку масу природного газу потрібно спалити, щоб розплавити олово? Вважайте що на нагрівання коробки з оловом витрачається 35% енергії, яка ВИДІЛЯЄТЬСЯ в ході повного згоряння газу. ​

Answer 1

Ответ:

2,7 г.

Объяснение:

Answer 2

To calculate the mass of natural gas needed to melt the tin in the iron box, we need to consider the energy required to heat the box and the energy released during the combustion of natural gas.

Given: - Mass of the iron box = 250 g - Mass of tin in the box = 150 g - Energy required to heat the box = 35% of the energy released during the combustion of natural gas

To solve this problem, we can follow these steps:

1. Calculate the energy required to heat the iron box: - The specific heat capacity of iron is approximately 0.45 J/g°C. - The temperature change required to melt tin is the difference between the melting point of tin (231.93°C) and room temperature (assumed to be 25°C). - The formula to calculate the energy required is: Q = m * c * ΔT, where Q is the energy, m is the mass, c is the specific heat capacity, and ΔT is the temperature change. - Substitute the values into the formula to find the energy required to heat the box.

2. Calculate the energy required to melt the tin: - The heat of fusion for tin is approximately 59.11 J/g. - The formula to calculate the energy required is: Q = m * ΔH, where Q is the energy, m is the mass, and ΔH is the heat of fusion. - Substitute the mass of tin into the formula to find the energy required to melt the tin.

3. Calculate the total energy required: - Add the energy required to heat the box and the energy required to melt the tin.

4. Calculate the mass of natural gas needed: - The energy released during the combustion of natural gas is approximately 55.5 MJ/kg. - Convert the total energy required to joules. - The formula to calculate the mass of natural gas is: mass = energy / (energy released per kilogram of natural gas).

Let's calculate the mass of natural gas needed to melt the tin in the iron box.

Calculation:

1. Calculate the energy required to heat the iron box: - Specific heat capacity of iron (c) = 0.45 J/g°C - Temperature change (ΔT) = 231.93°C - 25°C = 206.93°C - Energy required (Q1) = 250 g * 0.45 J/g°C * 206.93°C

2. Calculate the energy required to melt the tin: - Heat of fusion for tin (ΔH) = 59.11 J/g - Energy required (Q2) = 150 g * 59.11 J/g

3. Calculate the total energy required: - Total energy required (Q_total) = Q1 + Q2

4. Calculate the mass of natural gas needed: - Energy released per kilogram of natural gas = 55.5 MJ/kg = 55.5 * 10^6 J/kg - Convert the total energy required to joules. - Mass of natural gas needed = Q_total / (energy released per kilogram of natural gas)

Now, let's perform the calculations.

Calculation:

1. Calculate the energy required to heat the iron box: - Specific heat capacity of iron (c) = 0.45 J/g°C - Temperature change (ΔT) = 231.93°C - 25°C = 206.93°C - Energy required (Q1) = 250 g * 0.45 J/g°C * 206.93°C = 23,081.25 J

2. Calculate the energy required to melt the tin: - Heat of fusion for tin (ΔH) = 59.11 J/g - Energy required (Q2) = 150 g * 59.11 J/g = 8,866.5 J

3. Calculate the total energy required: - Total energy required (Q_total) = Q1 + Q2 = 23,081.25 J + 8,866.5 J = 31,947.75 J

4. Calculate the mass of natural gas needed: - Energy released per kilogram of natural gas = 55.5 MJ/kg = 55.5 * 10^6 J/kg - Convert the total energy required to joules: 31,947.75 J - Mass of natural gas needed = 31,947.75 J / (55.5 * 10^6 J/kg)

The mass of natural gas needed to melt the tin in the iron box is approximately 0.576 kg.

Please note that the calculations provided are based on the given information and assumptions.