Question 47: Thermodynamics & KTG

Question

The latent heat of vaporisation of water is $$2240 \mathrm{~J}$$. If the work done in the process of vaporisation of $$1 \mathrm{~g}$$ is $$168 \mathrm{~J}$$, the increase in internal energy is

Accepted Answer

The latent heat of vaporisation, also known as the enthalpy of vaporisation, reflects the energy required to transform a substance from a liquid phase to a gas phase without changing its temperature. According to the first law of thermodynamics, the change in internal energy (ÃÂU) during the process of vaporisation can be calculated using the formula:
$$ÃÂU = Q - W$$
Where:
$$Q$$ is the heat added (latent heat of vaporisation)
$$W$$ is the work done in the process
In this scenario:
The latent heat of vaporisation ($$Q$$) is $$2240 \mathrm{~J}$$.
The work done ($$W$$) is $$168 \mathrm{~J}$$.
Substituting these values into the equation, we get:
$$ÃÂU = 2240 \mathrm{~J} - 168 \mathrm{~J}$$
Therefore,
$$ÃÂU = 2072 \mathrm{~J}$$
Hence, the increase in internal energy is:
Option B: 2072 J

Answer

1408 J

Answer

2072 J

Answer

2208 J

Answer

2408 J

Thermodynamics & KTG

The latent heat of vaporisation of water is $2240 \mathrm{~J}. If the work done in the process of vaporisation of 1 \mathrm{~g} is 168 \mathrm{~J}$, the increase in internal energy is

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