More practice questions

4. Q4. How much heat raises the temperature of 1 mol of helium by 10 K (a) at constant volume, (b) at constant pressure? Use NCERT Table 10.4.

   Show answerHide answer

   (a) C_vΔT = 12.5 × 10 = 125 J. (b) C_pΔT = 20.8 × 10 = 208 J. More heat is needed at constant pressure because the gas also does work as it expands.

5. Q5. What are the SI units of heat capacity, specific heat capacity and molar specific heat capacity?

   Show answerHide answer

   J K^⁻¹, J kg^⁻¹ K^⁻¹ and J mol^⁻¹ K^⁻¹.

6. Q6. Equal masses of lead and water receive the same amount of heat. How many times larger is the temperature rise of the lead? Use NCERT Table 10.3.

   Show answerHide answer

   ΔT ∝ 1/s, so the ratio is 4186/127.7, about 32.8: the lead warms about 33 times as much.