kilocalories released when 20.0 g of steam condenses at 100 degrees C. and the liquid cools to 0 degrees C.
To calculate the kilocalories released when steam condenses and cools, we need to consider two steps: the energy released during condensation and the energy released during cooling.
First, let's calculate the energy released during condensation. When steam condenses, it undergoes a phase change from a gas to a liquid, releasing heat. The heat released during condensation can be calculated using the formula:
Energy released = mass of substance × heat of vaporization
The heat of vaporization for water is approximately 540 calories/gram. However, since we need the answer in kilocalories, we need to convert calories to kilocalories by dividing by 1000.
Let's calculate the energy released during condensation:
Energy released during condensation = (20.0 g) × (540 calories/g) ÷ (1000 calories/kcal)
Next, we need to calculate the energy released during cooling. When the liquid cools from 100 degrees C to 0 degrees C, it loses heat. The amount of heat released can be calculated using the formula:
Energy released = mass of substance × specific heat capacity × change in temperature
The specific heat capacity of water is approximately 1 calorie/gram/degree Celsius. Again, we need to convert the result to kilocalories by dividing by 1000.
Let's calculate the energy released during cooling:
Energy released during cooling = (20.0 g) × (1 calorie/g/°C) × (100 °C - 0 °C) ÷ (1000 calories/kcal)
Finally, to get the total energy released, we need to sum up the energy released during condensation and cooling:
Total energy released = Energy released during condensation + Energy released during cooling
Now you can calculate the kilocalories released when 20.0 g of steam condenses at 100 degrees C and cools to 0 degrees C by plugging in the values into the formulas above and performing the arithmetic.