How many kilograms of water can be evaporated at 100 degrees Celsius by the combustion of 470 litres of fuel oil whose heat of combustion is 37 MJ/Litre
heat=Lf*mass
37E6*370=Lf*mass
so use heat of vaporization Lf in J/kg
To calculate the amount of water that can be evaporated, we need to consider the heat released by the combustion of fuel oil and the heat required to evaporate the water.
First, let's calculate the total heat released by the combustion of fuel oil:
Heat of combustion of fuel oil = 37 MJ/Litre
Volume of fuel oil = 470 litres
Total heat released = Heat of combustion * Volume of fuel oil
Total heat released = 37 MJ/L * 470 L
Total heat released = 17,390 MJ (megajoules)
Next, let's calculate the heat required to evaporate water:
The heat required to evaporate water can be approximated using the specific heat capacity of water and the heat of vaporization.
Specific heat capacity of water = 4.18 J/g°C (joules per gram per degree Celsius)
Heat of vaporization of water = 2260 J/g (joules per gram)
Since we're looking for the amount of water in kilograms, we need to convert the volume from litres to kilograms.
1 litre of water = 1 kilogram of water
Now, let's determine the amount of water that can be evaporated:
Total heat released / Heat required to evaporate water = Mass of water
Total heat released = 17,390 MJ * 10^6 J/MJ (converting from megajoules to joules)
Heat required to evaporate water = Specific heat capacity of water * Change in temperature + Heat of vaporization of water
Let's assume the initial temperature of water is 20°C and we want to heat it to 100°C.
Change in temperature = Final temperature - Initial temperature
Change in temperature = 100°C - 20°C = 80°C
Heat required to evaporate water = 4.18 J/g°C * 80°C + 2260 J/g (converting from Celsius to Kelvin)
Now, we can calculate the mass of water:
Mass of water = Total heat released / Heat required to evaporate water
Once we have the mass of water, we can convert it to kilograms by dividing by 1000.
Now, let's plug in the values to calculate the amount of water that can be evaporated.