How much heat is required to convert 9 grams of water at 100 degrees C into steam at 100 degrees C. Hvap for water = 40.7 kJ/mol

mass x heat vap = ??

To calculate the heat required to convert 9 grams of water at 100 degrees Celsius into steam at 100 degrees Celsius, we need to consider two steps:

1. Heating the water from 100 degrees Celsius to its boiling point.
2. Converting the water at its boiling point to steam.

Step 1: Heating the water to its boiling point
To calculate the heat required to increase the temperature of the water, we can use the specific heat capacity of water, which is 4.18 J/g°C.
The temperature change is 100°C - 0°C = 100°C.

Heat = mass × specific heat capacity × temperature change
Heat = 9 g × 4.18 J/g°C × 100°C
Heat = 3762 J

Step 2: Converting water to steam
To calculate the heat required for the phase change from water to steam, we need to use the enthalpy of vaporization (Hvap) value given as 40.7 kJ/mol.
First, we need to convert the mass of water to the number of moles. The molar mass of water (H2O) is approximately 18 g/mol.

Number of moles = mass / molar mass
Number of moles = 9 g / 18 g/mol
Number of moles = 0.5 mol

Heat = number of moles × Hvap
Heat = 0.5 mol × 40.7 kJ/mol
Heat = 20.35 kJ = 20350 J

Total heat required = heat from step 1 + heat from step 2
Total heat required = 3762 J + 20350 J
Total heat required = 24112 J

Therefore, it would require approximately 24112 Joules (or 24.112 kJ) of heat to convert 9 grams of water at 100 degrees Celsius into steam at 100 degrees Celsius.

To determine the amount of heat required to convert a given amount of water at 100 degrees Celsius into steam at 100 degrees Celsius, we need to consider the heat of vaporization (Hvap) and the molar mass of water.

Here's how we can approach this problem:

Step 1: Determine the moles of water:
Given the mass of water is 9 grams.
To convert grams to moles, we use the molar mass of water, which is approximately 18 g/mol. So, the moles of water can be calculated as:
moles of water = mass of water / molar mass of water

moles of water = 9 g / 18 g/mol
moles of water = 0.5 mol

Step 2: Calculate the heat required:
The heat required to convert 1 mole of water from a liquid to a gas is given as Hvap (heat of vaporization) which is 40.7 kJ/mol.

To find the heat required to convert 0.5 moles of water, we multiply the moles by the heat of vaporization:
heat required = moles of water * Hvap

heat required = 0.5 mol * 40.7 kJ/mol
heat required = 20.35 kJ

Therefore, to convert 9 grams of water at 100 degrees Celsius into steam at 100 degrees Celsius, approximately 20.35 kJ of heat is required.