A cold trap is set up to cause molecules to linger near the suction in a vacuum system.If the cold trap has an effective volume of .200 L and is maintained at 13.0 K,how many molecules are in it at 10.0 Pa of pressure? (Avogadro's number is 6.022 × 10²³ mol^-1,and the universal gas constant is 8.314 J/K · mol.Assume the behavior of an ideal gas. )

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Using the ideal gas law, PV = nRT, we can solve for n (number of moles): n = PV/RT. Substituting the given values (P = 10.0 Pa, V = 0.200 L = 0.0002 m³, R = 8.314 J/K·mol, T = 13.0 K), we find n ≈ 1.84 × 10⁻⁵ mol. Multiplying by Avogadro's number gives the number of molecules: 1.84 × 10⁻⁵ mol × 6.022 × 10²³ molecules/mol ≈ 1.11 × 10¹⁹ molecules.

A Cold Trap Is Set Up to Cause Molecules to Linger