Calculation of External Work Done

Given:
- Amount of water boiled = 1 g
- Pressure = 1 atm
- Volume of steam produced = 1671 cm^3

Conversion:
To calculate the external work done, we need to convert the given values into SI units.

1 atm = 101325 Pa
1 cm^3 = 1 x 10^-6 m^3

Conversion of Pressure:
1 atm = 101325 Pa

Conversion of Volume:
1671 cm^3 = 1671 x 10^-6 m^3

Calculation of External Work Done:
The external work done is given by the equation: W = PΔV

Where:
W = External work done
P = Pressure
ΔV = Change in volume

Substituting the given values:
W = (101325 Pa) x (1671 x 10^-6 m^3)

W = 169.369 J

Therefore, the external work done when 1 g of water is boiled at 1 atm pressure is 169.369 Joules.

Explanation:
When water is boiled, it undergoes a phase change from a liquid to a gas. The energy required for this phase change is known as the latent heat of vaporization. As the water molecules gain enough kinetic energy, they break free from the liquid phase and enter the gaseous phase.

During this process, the water molecules expand and occupy a larger volume. The external work done is the energy required to push back the surroundings and create this expansion. It can be calculated using the equation W = PΔV, where P is the pressure and ΔV is the change in volume.

In this case, the pressure is given as 1 atm, which is equivalent to 101325 Pa. The volume of steam produced is given as 1671 cm^3, which is equivalent to 1671 x 10^-6 m^3. By substituting these values into the equation, we can calculate the external work done.

The calculated value of 169.369 Joules represents the energy required to push back the surroundings and create the expansion of the steam.