Question

A brass boiler has a base of 0.15 m2 and thickness 1.0 cm. If boils water at the rate of 6.0 kg/min when placed on a gas stove. Estimate the temperature of the part of the flame in contact with the boiler. Thermal conductivity of brass = 109 Js-1 m-1 °C-1.(Heat of vaporization of water = 2256 X 103 J kg-1).

Answer 1

Here, base area A = 0.15 m2

Here, T = temperature of the part of the flame in Contact With boiler. Rate of boiling of water = 6 kg min-1. Rate at Which heat is being Supplied to water is:

= 2.2556 X 105 Js-1

Equating the above two values of Δθ/Δt

1635 (T - 1000) = 2.256 X 105

⇒ T - 100 = (2.256 X 105)/ 1635 = 138

∴ T = 138 + 100 = 238 °C.