Question

A 0.250-kg block of a pure material is heated from 20.0°C to 65.0°C by the addition of 4.35 kJ of energy. Calculate its specific heat and identify the substance of which it is most likely composed.

(a) 0.84 kJ/kg°C, Copper
(b) 1.25 kJ/kg°C, Aluminum
(c) 2.70 kJ/kg°C, Lead
(d) 0.46 kJ/kg°C, Iron

Answer 1

The specific heat of the substance is 2.70 kJ/kg°C, and it is likely composed of Lead.

Step-by-step explanation:

To calculate the specific heat of the substance, we can use the formula:

q = mc∆T

Where q is the energy added, m is the mass, c is the specific heat, and ∆T is the change in temperature.

Plugging in the given values:

4.35 kJ = (0.250 kg) * c * (65.0°C - 20.0°C)

Solving for c, we find that the specific heat of the substance is 2.70 kJ/kg°C.

We can now identify the substance based on its specific heat. Looking at the options, the substance most likely composed of is Lead which has a specific heat of approximately 0.13 J/g°C or 0.130 kJ/kg°C.