5 . If a 360 mL sample of helium contains 0.25 mol of the gas, how many molecules of
chlorine gas would occupy the same volume at the same temperature and pressure?
(A) 1.2 × 10^24
(B) 6.022 × 10^23
(C) 3.01 × 10^23
(D) 1.51 × 10^23
(E) 7.55 × 10^226 . In the kinetic molecular theory of gases, which of the following statements concerning
average speeds is true?
(A) Most of the molecules are moving at the average speed.
(B) Any given molecule moves at the average speed most of the time.
When the temperature increases, more of the molecules will move at the new
average speed.(C)
When the temperature increases, fewer molecules will move at the new average
speed.(D)
(E) When the temperature increases, the average speed decreases.7 . What is the density of a gas at 76 torr and 37 ̊C (molar mass = 25 g/mol)?
(A) 0.1 g/L
(B) 0.8 g/L
(C) 22.4 g/L
(D) 75 g/L
(E) 633 g/L8 . The following reaction represents the production of hydrogen chloride gas.
H 2 + Cl 2 → 2HCl