Molecular Physics | Thermodynamics Answers

A Carnot engine has an efficiency of 40%. Its efficiency is to be raised to 50%. By
how much must the temperature of the source be increased if the sink is at 27 °C.

Define adiabatic lapse rate? Obtain an expression for adiabatic lapse rate for earth’s
atmosphere?

Using a suitable diagram, explain the most probable speed, the average speed and the root
mean square speed.

Why don't we feel cool when we are in front of sunshine, while evaporation is also taking place so rapidly?

A student wants to cool 0.25kg of Coke drink (mostly water), initially 25°C, by adding ice initially at -20°C. How much ice should be added so that the final temperature will be 0°C with all the ice melted if the heat capacity of the container may be neglected.

I just need help to solve a problem:

Show that (∂E/∂V)β, N + β(∂p/∂β)N, V = - p

PS: There is a bar over E and over p (this in both sides) - meaning that is an average.

The temperature of a 46.4 g sample of a metal is raised from 21.3 degrees celsius to 55.9 degrees celcius when 400.6 cal of heat are added. The specifc heat capacity of the sample is what in cal/g*oC.

a closed vesswl having capacity200ml is filled with hydrogen gas STP. calculate:
number of moles of hydrogen gas filled in the vessel
pressure of hydrogen gas in the vessel ai 273 degree c
root mean square velocity of hydrogen gas at STP
the value of Cp and Cv for hydrogen gas

Find difference between the mean square speeds of hydrogen and oxygen molecules at N.T.P. Take molecular weight of hydrogen and oxygen as 2 and 32.

Two vesseles having volume of 5 litres and 3 litres contain air at pressure of 3 atmosphere and 7 atmospheres resp. What will be the resultant presure when they are connected together with a small tube? Assume temperature remains constant throughout.