Molecular Physics | Thermodynamics Answers

Which of the following molecule exhibits rotational Raman spectrum
1)CH4
2)CF4
3)CCL4
4)C2

Monoatomic gases give
1)bonds composed of closely spaced lines
2) continuous lines
3)distinct bright emission lines

An open flask contains air at 27°C. To what temperature at which 2/5 th mass of air escapes the flask

Determine the temperature, volume, internal energy, enthalpy, entropy and density of 2kg of
steam at a pressure of 2MM/m2 and with a dryness fraction of 0.85.

Two identical gaseous systems, each containing 0.06 mol of ideal gas are at 300 K and 2.0 atm pressure. The ratio of heat capacities of the gas is 1.4. One of the gases is made to expand adiabatically and the other isothermally until they are at normal pressure. Calculate the final volumes in each case.

The main constituents of air are 80% of nitrogen molecules of molar mass 28 kg/k mol and
20% oxygen molecules of molar mass 32 kg/k mol. The mass of air in 50 cm3 volume at
9.3 × 104 Pa pressure at room temperature (20°C) is
[use ideal gas law] (R = 8.314 × 103 J/k mol/K)
(1) 5.5 kg (2) 55 × 10–3 kg
(3) 55 kg (4) 5.5 × 10–5 kg

What is the speed of sound (in m/s) in air at the normal boiling temperature of water?

A
180-Hz
sound travels through pure helium. The wavelength of the sound is measured to be
5.59 m.
What is the speed of sound in helium?

What frequency of sound traveling in air at 20°C has a wavelength equal to
1.7 m,
the average height of a person?

Ultrasound probes can resolve structural details with sizes approximately equal to the wavelength of the ultrasound waves themselves. What is the size of the smallest feature observable in human tissue when examined with
15-MHz
ultrasound? The speed of sound in human tissue is 1,540 m/s.