A child running a temperature of 101°F is given an antipyrin (i.e. a medicine that lowers fever) which causes an increase in the rate of evaporation of sweat from his body. If the fever is brought down to 98 °F in 20 minutes, what is the average rate of extra evaporation caused, by the drug. Assume the evaporation mechanism to be the only way by which heat is lost. The mass of the child is 30 kg. The specific heat of human body is approximately the same as that of water, and latent heat of evaporation of water at that temperature is about 580 cal g¯¹
The P - T phase diagram of Carbon dioxide ( CO 2 ) is shown in the figure below.
a)
From the graph, it is clear that the equilibrium point (C) of the all three phases of CO 2 exist at the triple point at temperature − 56.6 ° C and pressure is 5.11 atm .
b)
With the decrease in pressure, the boiling and fusion point of CO 2 decreases accordingly. It can be found easily through the graph.
c)
The critical temperature and pressure of CO 2 is that point after which CO 2 will not liquefy or even if compressed to high pressure. Here, the value of the critical temperature of carbon dioxide is 31.1 ° C and the critical pressure of carbon dioxide is 73.0 atm .
d)
Form the phase diagram of carbon dioxide at different temperature and pressure, it lie in the different region.
The point ( − 70 ° C , 1.0 atm ) lies into the vapour region. Hence, CO 2 is vapour at this point.
The point ( − 60 ° C , 10 atm ) lies into the solid region. Hence CO 2 is solid at this point.
The point ( 15 ° C , 56 atm ) lies into the liquid region. Hence CO 2 is liquid at this point.
The
a)
From the graph, it is clear that the equilibrium point (C) of the all three phases of
b)
With the decrease in pressure, the boiling and fusion point of
c)
The critical temperature and pressure of
d)
Form the phase diagram of carbon dioxide at different temperature and pressure, it lie in the different region.
The point
The point
The point
