Question

How much heat is needed to vaporize 10.0 kg of mercury At it’s boiling point?A temperature of a 0.25 kg sample of copper decreases from 75.0 °C to 25.0 °C. How much heat flows out of the copper sample?

Answer 1

Given data

*The given mass of mercury is m = 10.0 kg

*The value of latent heat of vaporization of mercury is

`L_v=2.7*10^5\text{ J/kg}`

The formula for the heat is needed to vaporize 10.0 kg of mercury at its boiling point is given as

`Q=mL_v`

Substitute the known values in the above expression as

`\begin{gathered} Q=(10.0)(2.7*10^5) \\ =2.7*10^6\text{ J} \end{gathered}`

Hence, the heat is needed to vaporize 10.0 kg of mercury at its boiling point is Q = 2.7 × 10^6 J