2gm of steam condenses when passed through 40 gm of water initially at `25^(@)C` . The condensation of steam raises the temperature of water to `54.3^(@)C` . What is the latent heat of steam

Options

A. 540 cal/g
B. 536 cal/g
C. 270 cal/g
D. 480 cal/g

Answer

A

Explanation

Let L be the latent heat and using principle of calorimetry.
`2L + 2(100-54.3)` = `40 xx (54.3 -25.3)`
`rArr` L = 540.3cal/g`