University Physics Al No ll Kinetic Theory Class Number ame I. Choose the Correct Answer Which type of ideal gas will have the largest value for Cp-Cv? (D) (A)Monatomic (B) Diatomic (C) Polyatomic (D) The value will be the same for all Solution The difference between the molar specific heat at constant pressure and that at constant volume equal to the universal gas constant Cp-CV=R 2. What would be the most likely value for CT, the molar heat capacity at constant temperature? (A)0 (B)O<C< Cv (C)Cr<CT <CP (D)CToo Using the definition of the molar specific heat: C hen T= constant, the molar n dT heat capacity is CT=∞ 3. Which of the following speeds divides the molecules in a gas in thermal equilibrium so that half have speeds faster, and half have speeds slower? (A)Vp (C)vms (D) Non of the above Solution According to the physical meaning of v,, Vav, and vms, non of them divides the molecules in a gas so that half have speeds faster, and half have speeds slower 4. Which of the following speeds corresponds to a molecule with the average kinetic energy? (A) (C)vm (D)Non of the above Solution The average kinetic energy is KEme =)m(v2),and for vm =v v),we have KEwe=mvms Then the answer is(C)University Physics AI No. 11 Kinetic Theory Class Number Name I．Choose the Correct Answer 1. Which type of ideal gas will have the largest value for CP-CV? （ D ） (A) Monatomic (B) Diatomic (C) Polyatomic (D) The value will be the same for all. Solution: The difference between the molar specific heat at constant pressure and that at constant volume is equal to the universal gas constant: CP-CV = R. 2. What would be the most likely value for CT, the molar heat capacity at constant temperature? （ D ） (A) 0 (B) 0< CT < CV (C) CV <CT <CP (D) CT=∞ Solution: Using the definition of the molar specific heat: T Q n Cmolar d 1 d = , so when T = constant, the molar heat capacity is CT=∞. 3. Which of the following speeds divides the molecules in a gas in thermal equilibrium so that half have speeds faster, and half have speeds slower? （ B ） (A) vp (B) vav (C) vrms (D) Non of the above. Solution: According to the physical meaning of av rms v , v , and v p , non of them divides the molecules in a gas so that half have speeds faster, and half have speeds slower. 4. Which of the following speeds corresponds to a molecule with the average kinetic energy? （ C ） (A) vp (B) vav (C) vrms (D) Non of the above Solution: The average kinetic energy is 2 2 1 KE m v ave = , and for 2 v v rms = , we have 2 2 1 KEave = mvrms , Then the answer is (C)