Answered

A hot iron ball of mass 200 g is cooled to a temperature of 22°C. 6.9 kJ of heat is lost to the surroundings during the process. What was the initial temperature of the ball? (ciron = 0.444 J/g°C)

A)

23°C

B)

78°C

C)

100°C

D)

155°C

Verified Answer :

olemakpadu

Heat lost or gained, H = mc(θ₂ - θ₁) 
Where m = mass, c = Specific heat capacity, θ₂= final temperature, θ₁ = initial temperature

m = 200g, c = 0.444 J/g°C, θ₁ = 22 °C  (Since it was cooled).

H = 6.9 kj = 6.9 1000J = 6900 J

6900 = 2000.444 (θ₂ - 22)

6900/(2000.444)  =  θ₂ - 22

77.70 = θ₂ - 22

θ₂ - 22 = 77.7

θ₂      =  77.7 + 22 = 99.7

So initial temperature before cooling ≈ 100°C .  Option C.

Answer:

The answer is C) 100°C

Explanation:

It's on USATestprep.

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