Concepts Of Physics MCQ Edition [Volume 2]PhysicsKinetic Theory of Gases
Determine the number of molecules of an ideal gas present in a volume of 1.000 cm ^3 at STP.
Options
- A6.02 10¹⁹
- B2.69 10²⁵
- C2.69 10¹⁹
- D2.69 10¹⁶
Correct answer
C. 2.69 10¹⁹
Step-by-step solution
At STP, 1 mole of an ideal gas occupies a volume of 22.4 L or 22400 cm ^3 . The number of moles in 1.000 cm ^3 of the gas is: n = 1 22400 mol The number of molecules is given by N = n N_A , where Avogadro's number N_A = 6.022 10²³ mol ⁻¹ . N = 1 22400 6.022 10²³ N = 6.022 2.24 10¹⁹ 2.69 10¹⁹