Write a latent heat unit and dimensional formula. On what does the value of latent heat depend ?

Answer the following questions based on the $P$ - $T$ phase diagram of carbon dioxide:

$(a)$ At what temperature and pressure can the solid, liquid and vapour phases of $CO _{2}$ co-exist in equilibrium?

$(b)$ What is the effect of decrease of pressure on the fusion and boiling point of $CO _{2} ?$

$(c)$ What are the critical temperature and pressure for $CO _{2} ?$ What is their sıgnificance ?

$(d)$ Is $CO _{2}$ solid, liquid or gas at $(a)\;-70\,^{\circ} C$ under $1\; atm$, $( b )\;-60\,^{\circ} C$ under $10 \;atm,$ $(c)$ $15\,^{\circ} C$ under $56$ atm ?

Heat is supplied to a certain homogenous sample of matter, at a uniform rate. Its temperature is plotted against time, as shown. Which of the following conclusions can be drawn

The latent heat of vaporization of a substance is always

Two substances $A$ and $B$ of equal mass m are heated at uniform rate of $6\, cal s^{-1}$ under similar conditions. $A$ graph between temperature and time is shown in figure. Ratio of heat absorbed ${H_A}/{H_B}$ by them for complete fusion is

A closed bottle containing water at $30^{\circ} C$ is open on the surface of the moon. Then,