Worksheet Chapter 4: Heat

1. Define specific latent heat of fusion in words.

2. True or False: Charles's Law states that volume is inversely proportional to temperature in Kelvin at constant pressure.

3. An electric kettle rated at 2.2 kW contains 1.5 kg of water at 30°C. Calculate the time taken to heat the water to its boiling point of 100°C. (Specific heat capacity of water = 4200 J kg⁻¹ °C⁻¹)

4. A fixed mass of air in a syringe has a volume of 30 cm³ at 27°C and a pressure of 100 kPa. If the syringe is heated to 87°C while the pressure increases to 120 kPa, calculate the new volume of the air inside the syringe.

5. Fill in the blank: The temperature scale where 0 K represents absolute zero is known as the ________ temperature scale.

6. A metal block of mass 0.5 kg at 100°C is placed into 0.2 kg of water at 25°C inside an insulated container. The final equilibrium temperature reached by the mixture is 35°C. Calculate the specific heat capacity of the metal block. (c_water = 4200 J kg⁻¹ °C⁻¹)

7. True or False: When two objects reach thermal equilibrium, heat stops flowing between them entirely.

8. Explain briefly why a person feels cooler when sweat evaporates from their skin.

9. Calculate the total energy needed to convert 0.5 kg of ice at -10°C completely into steam at 100°C. (c_ice = 2100 J kg⁻¹ °C⁻¹, l_f = 3.34 × 10⁵ J kg⁻¹, c_water = 4200 J kg⁻¹ °C⁻¹, l_v = 2.26 × 10⁶ J kg⁻¹)

10. Which gas law explains why an inflated car tire increases in pressure after driving a long distance on a hot day?