Find the specific volume of saturated water vapour under standard pressure if a decrease of pressure by `Delta = 3.2 kPa` is known to decrease the water boiling temperature by `Delta T = 0.9 K`.

Explanation

Here `1 = liquid, 2 = Steam`
`Delta T = (T(V'_s - V'_(liq)))/(q_12) Delta P`
or `V'_s ~~ (q_12)/(T) (Delta T)/(Delta p) = (2250)/(373) xx (0.9)/(3.2) xx 10^-3 m^3//g = 1.7 m^3//kg`.