The portion $A B$ of the curve representing the state of matter denotes
Change from gaseous state to liquid state
The liquid state of matter
Gaseous state of matter
All of these
A block of ice at $-12^{\circ} C$ is slowly heated and converted into steam at $100^{\circ} C$. Which of the following curves best represents the event?
A quantity of heat required to change the unit mass of a solid substance, from solid state to liquid state, while the temperature remains constant, is known as
Two different liquids of same mass are kept in two identical vessels, which are placed in a freezer that extracts heat from them at the same rate causing each liquid to transform into a solid. The schematic figure below shows that temperature $T$ versus time $t$ plot for the two materials. We denote the specific heat of materials in the liquid (solid) states to be $C_{L 1}$ $\left(C_{S 1}\right)$ and $C_{L 2}\left(C_{S 2}\right)$, respectively. Choose the correct option given below.
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 ?
At temperatures close to $0\ K$ , the heat capacity $C$ of a certain solid is related to its temperature $T$ by the equation $C = aT^3$ , where a is a constant characteristic of the solid. Heat is supplied to the solid at a steady rate. Which graph best represents the variation of its temperature $T$ with time $t$ ?