The melting point of aluminum is 660°C,its latent heat of fusion is 4.00 × 10⁵ J/kg,and its specific heat is 900J/kg ∙ K.How much heat must be added to 500 g of aluminum originally at 27°C to completely melt it? A)485 kJ B)395 kJ C)273 kJ D)147 kJ E)14 kJ

Question

Quizplus · Accepted Answer

To completely melt 500 g of aluminum, we first need to calculate how much heat is required to raise the temperature of the aluminum from 27°C to its melting point of 660°C:

Q1 = mCΔT = (0.5 kg)(900 J/kg∙K)(660°C - 27°C) = 273,150 J

Next, we need to calculate the heat required to melt the aluminum:

Q2 = mL = (0.5 kg)(4.00 × 10^5 J/kg) = 200,000 J

The total amount of heat required is then:

Q = Q1 + Q2 = 273,150 J + 200,000 J = 473,150 J = 473.15 kJ

Rounding to two significant figures, the answer is 485 kJ, which corresponds to choice (A).

The Melting Point of Aluminum Is 660°C,its Latent Heat of Fusion