NEET Thermal Properties of Matter — Set 9

Question 1

A gas occupies $ 5 \, \text{L} $ at $ 2 \, \text{atm} $ and $ 27^\circ \text{C} $. If the pressure is increased to $ 4 \, \text{atm} $ and volume reduced to $ 3 \, \text{L} $, what is the final temperature in Celsius?

Accepted Answer

Given: $ V_1 = 5 \, \text{L} $, $ P_1 = 2 \, \text{atm} $, $ T_1 = 27^\circ \text{C} = 300 \, \text{K} $, $ P_2 = 4 \, \text{atm} $, $ V_2 = 3 \, \text{L} $. $ \frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2} $. $ T_2 = T_1 \times \frac{P_2}{P_1} \times \frac{V_2}{V_1} = 300 \times \frac{4}{2} \times \frac{3}{5} = 300 \times 2 \times 0.6 = 360 \, \text{K} $. $ t_C = T_2 - 273.15 = 360 - 273.15 \approx 86.85^\circ \text{C} \approx 87^\circ \text{C} $.

Question 2

Why does a metal rod expand more than a glass rod for the same temperature increase?

Accepted Answer

Metals have a higher coefficient of linear expansion ($ \alpha_l $) than glass (Section 10.5, Table 10.1). For the same $ \Delta T $, $ \Delta L = L_0 \alpha_l \Delta T $ is greater for metals due to their larger $ \alpha_l $.

Question 3

Which statement is true about the ideal gas equation?

Accepted Answer

The ideal gas equation ($ PV = nRT $) relates pressure, volume, and temperature for an ideal gas, where $ R $ is the universal gas constant and $ n $ is the number of moles.

NEET Physics: Thermal Properties of Matter — Practice Set 9

Q1. A gas occupies \( 5 \, \text{L} \) at \( 2 \, \text{atm} \) and \( 27^\circ \text{C} \). If the pressure is increased to \( 4 \, \text{atm} \) and volume reduced to \( 3 \, \text{L} \), what is the final temperature in Celsius?

Q2. Why does a metal rod expand more than a glass rod for the same temperature increase?

Q3. Which statement is true about the ideal gas equation?

Q4. Why does a calorimeter use a material with low specific heat capacity for its container?

Q5. A gas at \( 1 \, \text{atm} \) and \( 27^\circ \text{C} \) occupies \( 5 \, \text{L} \). What will be its volume at \( 2 \, \text{atm} \) and \( 127^\circ \text{C} \)?

Q6. Why does steam at \( 100^\circ \text{C} \) cause more severe burns than water at \( 100^\circ \text{C} \)?

Q8. A gas at \( 67^\circ \text{C} \) and \( 1.6 \, \text{atm} \) occupies \( 8 \, \text{L} \). If the temperature is reduced to \( 17^\circ \text{C} \) and volume adjusted to \( 6 \, \text{L} \), what is the final pressure?

Q9. What process occurs when dry ice changes directly from solid to vapor?

Q10. A gas at \( 2 \, \text{atm} \) and \( 47^\circ \text{C} \) occupies \( 6 \, \text{L} \). If the temperature drops to \( -3^\circ \text{C} \) and pressure becomes \( 1.5 \, \text{atm} \), what is the new volume?