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In a flow calorimeter, heat is supplied at a steady rate to a liquid flowing through it, and the steady-state temperature rise between inflow and outflow is measured to find the liquid's specific heat. A liquid of density 0.2 g/cm³ flows at 10 cm³/s. A 250 W coil supplies the heat, and a steady temperature difference of 25 deg C is established. Find the specific heat of the liquid.

1. 1 cal g⁻¹ deg C⁻¹
2. 2 cal g⁻¹ deg C⁻¹
3. 3 cal g⁻¹ deg C⁻¹
4. 4 cal g⁻¹ deg C⁻¹

Correct answer: 1 cal g⁻¹ deg C⁻¹

Solution

Mass flow = 0.2*10 = 2 g/s; c = P/(mdot*deltaT) = 5000/(2*25) = 100 J/g... = ~1.19 cal/g/deg C, closest to 1.

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