Molecular Physics | Thermodynamics Answers

How the phase change in which a gas changes into a liquid by losing heat energy is called?

1. A certain gas can be described by the following equation of state:
(p+a/V2)(V-b)=nRT
p, T and V are resp. the pressure, the temperature and the volume. a and b are the so-called van der Waals parameters.
Compute w, U and q is 1 mol of this gas expands reversible and isothermal from V1 to V2.
Note that: (dU/dV)T=T.(dp/dT)v-p

People partially cool themselves by sweating, which releases water that evaporates. If during exercise a human "burns" 1000 kcal(4184 kJ) in one hour of exercise, how many grams of water must evaporate at a body temperature of 37 degree celsius?
Assuming only 75 percent of the sweat evaporates (the rest being retained by the exercise clothes), how many grams of sweat must actually be produced?

5 moles = ?????? liters
(1 mole = 22.4 liters)

and how many molecules are in 50 liters?

3 moles is how many molecules? (mole = 6.02 * 10^23 molecules)

Dear physicist,

When a tray contains some water ,Why the speed of the waves depends on the depth of the water?

Please help me.

Consider heating the plasma through the adiabatic compression. Because of the invariance of μ, with the increasing of B the value of kT must also grow. But the magnetic field can not accelerate particles, since the Lorentz force qv×B is always perpendicular to the velocity. Then how do the particles get energy?

Liquid column put in conical tube moves by itself to more narrow part when it wets tube walls and to wider part when it does not wet the walls. Explain the phenomenon.

Is the ideal gas heated up or cooled if it expands at constant pressure?

Heat-insulated vessel with ideal gas is hanged on a rope in the gravity field. Due to the influence of force of gravity the density of gas in the bottom of the vessel is bigger than in the top. The rope is burned and the vessel freely falls. Supposedly, during the falling has time for forming of thermodynamic equilibrium, define equilibrium gas temperature, which will form in it in time of falling.