Question

Equal volume of aniline (R.D = 1.02) and water are allowed to cool from 55°C to 50°C in same surroundings. The time taken are 4 minute and 7.5 minute respecitvely. Specific heat of aniline is (nearly)

(1) 0.4 cal g^-1 (°C)^-1

(2) 0.4 J g^-1 (°C)^-1

(3) 0.52 cal g^-1 (°C)^-1

(4) 0.52 J kg^-1 (K)^-1

Answer 1

(3) 0.52 cal g^-1 (°C)^-1

Let m₁ and m₂ be mass of aniline and water respectively. Then

p₁ = density of aniline and p₂ = density of water. Let Q be heat lost by aniline of specific heat c₁ in cooling from 55°C to 50°C in time t₁ . Let θ°C be constant temperature of surrounding. Then from Newton’s law of cooling.