A student drops two metallic objects into a 120 g steel container holding) 150 g of water at 25°C. One object is a 253 g cube of copper that is initially at 85°C, and the other is a chunk of aluminum that is initially at 5°C. To the surprise of the student, the water reaches a final temperature of 25°C, its initial temperature. What is the mass of the aluminum chunk? (please add an explanation)

The mass of the aluminum chunk dropped into the water is 325.5 g.

The given parameters;

Apply the principle of conservation of energy, the heat gained by the aluminum is equal to heat lost by the copper;

Thus, the mass of the aluminum chunk dropped into the water is 325.5 g.

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0.326kg

Explanation:

Given the following :

Mass of copper (Mc) = 253g

Initial temperature of copper (t1) = 85°C

Mass of aluminium(Ma)=?

Initial temperature of aluminum(t1) = 5°C

Specific heat capacity of aluminum(Ca) = 900

Specific heat capacity of copper (Cc) = 387

Final temperature(t2) = 5°C

Q = mc(t2 - t1)

Ma × Ca × (t2 - t1)a = Mc × Cc × (t2 - t1)c

Ma × 900 × (25 - 5) = 0.253 × 387 × (25 - 85)

Ma × 900 × 20 = 0.253 × 387 × 60

Ma × 18000 = 5874.66

Ma = 5874.66 / 18000

Ma = 0.32637

Ma = 0.326kg