Observe the given curve carefully and mark the correct statement.

Options

A. `T_1` is the melting point and dry ice changes to `CO_2` gas from time `t_1` to `t_2`.
B. `T_1` is the boiling point and water vapours change to water from time `t_1` to `t_2`.
C. `T_1` is the freezing point and molten copper(II) sulphate changes to solid copper(II) sulphate from time `t_1` to `t_2`.
D. `T_1` is the melting point and solid copper(II) sulphate changes to molten copper(II) sulphate from time `t_1` to `t_2`.

Answer

C

Explanation

The given curve is the cooling curve. Melting and boiling of a substance are the heating phenomena while freezing of a substance is a cooling phenomenon. Thus, `T_1` is the freezing point at which a substance from a liquid state changes to the solid state from time `t_1` to `t_2`.