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The latent heat of vaporisation of water is 2,240 J. If the work done in the process of vaporisation of 1g is 168 J, then the increase in internal energy is?

Correct Answer: 2072 J
From the first law of thermodynamics, dQ = mL = dU + dW dU = m L – dW = 1×2240-168 dU = 2072 J.

In a surface condenser, the water flowing through a series of tubes at the rate of 200 kg/hr is heated from 15 degree Celsius to 75 degree Celsius. The steam condenses on the outside surface of tubes at atmospheric pressure and the overall heat transfer coefficient is estimated at 860 k J/m2 hr degree. Find the effectiveness of the heat exchanger. At the condensing pressure, stream has a saturation temperature 0f 100 degree Celsius and the latent heat of vaporization is 2160 k J/kg. Further, the steam is initially just saturated and the condensate leaves the exchanger without sub-cooling i.e. only latent heat of condensing steam is transferred to the water. Take specific heat of water as 4 k J/kg K

In a surface condenser, the water flowing through a series of tubes at the rate of 200 kg/hr is heated from 15 degree Celsius to 75 degree Celsius. The steam condenses on the outside surface of tubes at atmospheric pressure and the overall heat transfer coefficient is estimated at 860 k J/m2 hr degree. Find the number of transfer units of the heat exchanger. At the condensing pressure, stream has saturation temperature 0f 100 degree Celsius and the latent heat of vaporization is 2160 k J/kg. Further, the steam is initially just saturated and the condensate leaves the exchanger without sub-cooling i.e. only latent heat of condensing steam is transferred to water. Take specific heat of water as 4 k J/kg K

Consider the following statements.
1. Steam at 100°C and boiling water at 100°C contain same amount of heat.
2. Latent heat of fusion of ice is equal to the latent heat of vaporization of water.
3. In an air conditioner, heat is extracted from the room air at the evaporator coils and is ejected out at the condensor coils.
Which of these statements is/are correct?

An equipment which converts the latent or sensible heat of one fluid into the latent heat of vaporisation of another, is called a

Work done by A in one day is half of the work done by B in one day. Work done by B is half of the work done by C in one day. If C alone can complete the work in 7 days, in how many days can A, B and C together complete the work ?

A body has 15J of heat energy in a particular state. At the same state it has an internal energy of 30J. Assume no work is done, what will happen to the internal energy if 5J of heat is added to the system?

You are working with three networks that have the network IDs 192.168.5.0, 192.168.6.0, and 192.168.7.0. What subnet mask can you use to combine these addresses into one?

A stone has initial potential, kinetic and internal energy 7 J, 10 J and 2x J respectively, if the final kinetic energy, potential energy and internal energy are 5 J, 21 J and x respectively, what is the final internal energy?

In a thermal process, the pressure of a fixed mass of a gas is changed in such a manner that the gas molecules give out the heat of 30J and work of 10J is done on the gas. If the initial internal energy of the gas was 40 J, then the final internal energy will be?

Are these statements about the latent heat true? Statement 1: Heat absorbed or released as the result of a phase change is called latent heat. Statement 2: There is no change in the kinetic energy of particles in the material during phase change.