22-30. (a) The mean free path is the average distance a molecule travels before colliding with another molecule. The mean free path, A, is given by A = kT/(V20P), where k is Boltzmann's constant, T is temperature (K), P is pressure (Pa), and o is the collision cross section. For a molecule with a diameter d, the col- lision cross section is nd. The collision cross section is the area swept out by the molecule within which it will strike any other molecule it encounters. The magnetic sector mass spectrometer is maintained at a pressure of ~10¯³ Pa so that ions do not collide with (and deflect) one another as they travel through the mass analyzer. What is the mean free path of a molecule with a diam- eter of 1 nm at 300 K in the mass analyzer?

22-30. (a) The mean free path is the average distance a molecule travels before colliding with another molecule. The mean free path, A, is given by A = kT/(V20P), where k is Boltzmann's constant, T is temperature (K), P is pressure (Pa), and o is the collision cross section. For a molecule with a diameter d, the col- lision cross section is nd. The collision cross section is the area swept out by the molecule within which it will strike any other molecule it encounters. The magnetic sector mass spectrometer is maintained at a pressure of ~10¯³ Pa so that ions do not collide with (and deflect) one another as they travel through the mass analyzer. What is the mean free path of a molecule with a diam- eter of 1 nm at 300 K in the mass analyzer?

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Chapter18: Raman Spectroscopy

Section: Chapter Questions

Problem 18.2QAP

See similar textbooks

Similar questions

G. Bakale et al. (J. Phys. Chem., 12477 (1996)) measured the mobility of singly charged C60− ions in a variety of nonpolar solvents. In cyclohexane at 22 °C (viscosity is 0.93 × 10−3 kg m−1 s−1), the mobility is 1.1 × 10−4 cm2 V−1 s−1. Estimate the effective radius of the C60− ion. Suggest a reason why there is a substantial difference between this number and the van der Waals radius of neutral C60.
A solid surface with dimensions 2.5 mm × 3.0 mm is exposed to argon gas at 90 Pa and 500 K. How many collisions do the Ar atoms make with this surface in 15 s?
A one-dimensional polymer chain consists of 700 segments, each 0.90 nm long. If the chain were ideally flexible, what would be the root-mean-square separation of the ends of the chain?
In a study of the catalytic properties of a titanium surface it was necessary to maintain the surface free from contamination. Calculate the collision frequency per square centimetre of surface made by O2 molecules at 300 K and (a) 100 kPa, (b) 1.00 Pa. Estimate the number of collisions made with a single surface atom in each second. The conclusions underline the importance of working at very low pressures (much lower than 1 Pa, in fact) in order to study the properties of uncontaminated surfaces. Take the nearest neighbour distance as 291 pm.
The velocity v with which a protein moves through water under the influence of an electric field varied with values of pH in the range 3.0 < pH < 5.0 according to the expression v/(μm s−1) = a + b(pH) + c(pH)2 with a = 0.80, b = −4.0 × 10−3, and c = −5.0 × 10−2. Identify the isoelectric point of the protein.
Fast in 5 min i will give u like indeed
For many years, the extraction of gold - that is, the separation of gold from other materials - involved the use of potassium cyanide: 4\;\mathrm{Au}+8\;\mathrm{KCN}+\mathrm{O_2}+2\;\mathrm{H_2O}\rightarrow4\;\mathrm{KAu(CN)_2}+4\;\mathrm{KOH}4Au+8KCN+O2+2H2O→4KAu(CN)2+4KOH What is the minimum amount of KCN in moles needed to extract 29.0 g (about an ounce) of gold?
It is observed that the critical micelle concentration of sodium dodecyl sulfate in aqueous solution decreases as the concentration of added sodium chlordie increases. Explain this effect.
The enthalpy of adsorption of ammonia on a nickel surface is found to be −155 kJ mol−1. Estimate the mean lifetime of an NH3 molecule on the surface at 500 K; assume τ0 = 1.0 × 10−14 s.
At 0 °C, the molar polarization of a liquid is 32.16 cm3 mol−1 and its mass density is 1.92 g cm−3. Calculate the relative permittivity of the liquid. Take M = 85.0 g mol−1.
Suppose an H2O molecule (μ = 1.85 D) approaches an anion. What is the favourable orientation of the molecule? Calculate the magnitude of the electric field (in volts per metre) experienced by the anion when the water dipole is (a) 1.0 nm, (b) 0.3 nm, (c) 30 nm from the ion.
A solid surface with dimensions 3.5 cm × 4.0 cm is exposed to helium gas at 111 Pa and 1500 K. How many collisions do the He atoms make with this surface in 10 s?