Liquid helium has a very low boiling point, 4.2 K, as well as a low latent heat of vaporization, equal to 2.09 x 104 J/kg. If energy is transferred to a container of liquid helium at the boiling point from an immersed electric heater at a rate of 10.0 W, how long does it take to boil away 2.00 kg of the liquid?

You have a spherical heater, outside diameter = 3.40 cm, immersed in a container of water. In order to keep the water in the container heated to a constant temperature of 35.0°C you adjust the temperature of the spherical heater. You reach a steady-state condition when the surface temperature of the spherical heater is at 79.0°C. Assuming the electrical efficiency of the heater is 100.0%, calculate the power required by the heater (i.e., calculate q). Ignore radiation.

A cylinder container is divided into two equal sections by thermally isolated, frictionless piston,as shown in the figure. One section contains water and the other air. The cylinder is isolated except the one face of the water section. Each section has an initial volume of 100 liter. The initial temperature of the air is 40 degees C and the water is 90 degrees C with steam quality of 10%. The water are heated slowly until the entire section of the water is filled with saturated steam. Find the final pressure and the amount of heat transported to the container. Assume: the heat transfer is a reversible process. Assume for ideal gas the following relation between p and v: (p2/p1)^((k-1)/k) = (v1/v2)^k-1 ; k=1.4

A student decides to conduct an experiment by using two different flasks and two different gas samples. In flask 1, there exists Neon (Ne) gas, whereas the second flask is filled with nitrogen (N2) gas. If both flasks are kept at 270 K, answer the following questions. (Note: Molar mass of N2 = 28.014 g mol1,molar mass of Neon = 20.1797 g mol, R= 8.31 J. mol1.K1, k=1.38 x 1023 J.K-1, Avogadro's number = 6.02 x 1023 mol1.) a) Find the average kinetic energy of one Neon molecule. b) Calculate the average kinetic energy (translational+rotational) of one nitrogen molecule by including rotational motion in your calculations. c) Find the root-mean-square speed of one neon molecule. V ms1 Check

The "steam" above a freshly made cup of instant coffee is really water vapor droplets condensing after evaporating from the hot coffee. What is the final temperature of 205 g of hot coffee initially at 98.0°C if 3.18 g evaporates from it? The coffee is in a Styrofoam cup, and so other methods of heat transfer can be neglected. Assume that coffee has the same physical properties as water; its latent heat of vaporization is 539 kcal/kg and its specific heat is 1.00 kcal/(kg · °C).

Water with a mass of mW = 0.400 kg and temperature of TW = 15.5°C is poured into an insulated bucket containing mI = 0.19 kg of ice at a temperature of TI = -15°C. Assume the specific heats of ice and water are constant at cI = 2.10×103 J/(kg⋅°C) and cW = 4.19×103 J/(kg⋅°C), respectively. The latent heat of fusion for water is Lf = 334×103 J/kg.  Part (a)  What is the final temperature of the mixture, in degrees Celsius?  Tfinal =         Part (b)  Enter an expression for the mass of ice, in kilograms, that has melted when the mixture reaches its final temperature.  mmelt =     Part (c)  Calculate how much ice, in kilograms, has melted when the mixture reaches its final temperature.  mmelt =