$A$ block of ice at $-10\,^oC$ is slowly heated and converted to steam at $100\,^oC.$ Which of the following curves represents the phenomenon qualitatively?

When vapour condenses into liquid,

The latent heat of vaporization of a substance is....

At $100^{\circ}C,$ the substance that causes the most severe burn is:

Liquid oxygen at $50\ K$ is heated to $300\ K$ at a constant pressure of $1\ atm$. The rate of heating is constant. Which of the following graphs represents the variation of temperature with time?

Two different liquids of the 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 the temperature $T$ versus time $t$ plot for the two materials. We denote the specific heat in the liquid states as $C_{L 1}$ and $C_{L 2}$ for materials $1$ and $2$, respectively, and the latent heats of fusion as $L_1$ and $L_2$, respectively. Choose the correct option.