Question

Какое количество теплоты выделилось при остывании воды, объём которой 20 л, если температура изменилась от 80 до 30 0С ? Ответ дайте в кДж помогите пожалуйста

Answer 1

Ответ:

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Answer 2

Calculation of Heat Released during Cooling of Water

To calculate the amount of heat released during the cooling of water, we can use the formula:

Q = mcΔT

Where: - Q is the heat released (in joules) - m is the mass of the water (in kilograms) - c is the specific heat capacity of water (in joules per kilogram per degree Celsius) - ΔT is the change in temperature (in degrees Celsius)

In this case, we are given that the volume of water is 20 liters and the temperature change is from 80°C to 30°C. We need to convert the volume to mass and use the specific heat capacity of water to calculate the heat released.

Conversion of Volume to Mass

To convert the volume of water to mass, we need to know the density of water. The density of water is approximately 1 gram per milliliter (g/mL) or 1000 kilograms per cubic meter (kg/m³).

Given that the volume of water is 20 liters, we can convert it to cubic meters by dividing by 1000:

Volume = 20 liters = 20/1000 = 0.02 cubic meters

Now, we can calculate the mass of water using the density:

Mass = Volume x Density = 0.02 cubic meters x 1000 kg/m³ = 20 kilograms

Calculation of Heat Released

Now that we have the mass of water, we can calculate the heat released using the formula mentioned earlier:

Q = mcΔT

Given: - m = 20 kilograms - c = specific heat capacity of water (approximately 4186 joules per kilogram per degree Celsius) - ΔT = change in temperature = 80°C - 30°C = 50°C

Substituting the values into the formula:

Q = 20 kg x 4186 J/kg°C x 50°C = 20 x 4186 x 50 = 4,186,000 joules

Therefore, the amount of heat released during the cooling of water with a volume of 20 liters, when the temperature changes from 80°C to 30°C, is approximately 4,186,000 joules or 4,186 kilojoules (kJ).

Please note that the specific heat capacity of water can vary slightly depending on the temperature range considered. The value used here is an average value.