CH.10. HEAT

The SI unit of thermal capacity is:

• J °C⁻¹

• J K⁻¹

• cal °C⁻¹

• cal K⁻¹

The principle of a calorimeter is based on the law of conservation of:

• mass

• energy

• temperature

• None of the above

If the temperature rises by 10°C, what is its equivalent rise on the Kelvin scale?

• 273 K

• 283 K

• 10 K

• 0 K

The specific heat capacity of glass is 670 J kg⁻¹ K⁻¹. What is the heat capacity of a glass beaker of mass 50 g?

• 335 J K⁻¹

• 33.5 J K⁻¹

• 13.4 J K⁻¹

• 1.34 J K⁻¹

A piece of iron of mass 5.5 kg has a thermal capacity of 2,656 J°C⁻¹. What is its specific heat capacity in SI units?

• 483 J kg⁻¹ K⁻¹

• 2656 J kg⁻¹ K⁻¹

• 14608 J kg⁻¹ K⁻¹

• None of the above

A piece of iron of mass 5.5 kg has a thermal capacity of 2,656 J°C⁻¹. How much heat in kJ is needed to warm it by 50°C?

• 265.6 kJ

• 132.8 kJ

• 53.12 kJ

• None of the above

Calculate the amount of heat energy required to raise the temperature of 200 g of lead from 30°C to 60°C. Specific heat capacity of lead is 130 J kg⁻¹ K⁻¹.

• 780 J

• 3900 J

• 1560 J

• 7800 J

2,000 J of heat energy is supplied to 200 g of copper to raise its temperature from 30°C to 55°C. Calculate the specific heat capacity of copper.

• 0.2 J g⁻¹ °C⁻¹

• 0.4 J g⁻¹ °C⁻¹

• 2 J g⁻¹ °C⁻¹

• 4 J g⁻¹ °C⁻¹

In an experiment to measure the specific heat capacity of copper, 0.02 kg of water at 70°C is poured into a copper calorimeter (with a stirrer) of mass 0.16 kg at 15°C. After stirring, the final temperature is found to be 45°C. If the specific heat of water is 4,200 Jkg⁻¹ °C⁻¹, what is the quantity of heat released per kg of water per 1°C fall in temperature?

• 420 J

• 4,200 J

• 2,100 J

• 84,000 J

In the same experiment as question 9, calculate the heat energy released by the water in cooling from 70°C to 45°C.

• 210 J

• 2,100 J

• 105 J

• 1,050 J