Question

Let 1.00 kg of liquid water at ${100}^{\circ }C$ be converted to steam at ${100}^{\circ }C$ by boiling at standard atmospheric pressure (which is 1.00 atm or 1.01 $\times$ 105 Pa) in the arrangement as shown. The volume of that water changes from an initial value of $1.00\times {10}^{-3}$ $m^3$ as a liquid to 1.671 $m^3$ as steam.

2. If the latent heat of vaporization is 2256 kJ/kg, how much energy is transferred as heat during the process?

• A. 2256 kJ
• B. 2425 kJ
• C. 2087 kJ
• D. 2137 kJ

Answer 1

The correct option is A

2256 kJ

The only process for which we need to provide heat is for the conversion of water to steam. Heat required for this process is calculated by the formula -
Q = L $\times$ m
where
L = latent heat of vaporization
m = mass of water.
Hence

Q = 2256 $\times$ 1 = 2256 kJ.