Question

Jasmine noted down the temperature of each day and the state of cocunut oil. What can be the approximate freezing point and melting point of the coconut oil?
$$\begin{array}{cc}\text{Temperature}{(}^0\text{C})& \text{State}\\ \text{26.5}& \text{Liquid}\\ \text{26}& \text{Liquid}\\ \text{24.5}& \text{Liquid}\\ \text{24}& \text{Solid}\\ \text{23}& \text{Solid}\\ \text{22.6}& \text{Solid}\end{array}$$

• A. Freezing point = 23 ${}^o$C
  Melting point = 24.5 ${}^o$C
• B. Freezing point = 24 ${}^o$C
  Melting point = 24 ${}^o$C
• C. Freezing point = 24 ${}^o$C
  Melting point = 26 ${}^o$C
• D. Freezing point = 22.6 ${}^o$C
  Melting point = 24 ${}^o$C

Answer 1

The correct option is B Freezing point = 24 ${}^o$C

Melting point = 24 ${}^o$C
Freezing point is temperature at which a substance changes its state from liquid to solid on cooling.

Melting point is the temperature at which a substance changes its state from solid to liquid on heating.

The temperature at which a substance freezes while cooling is same as the temperature at which it melts when it is heated.

From the table given in the question, coconut oil changes its state from liquid to solid at 24 ${}^o\text{C}$. So the freezing point of cocunut oil is 24 ${}^o\text{C}$.
Since freezing point = melting point, therefore, melting point of coconut oil is also 24 ${}^o\text{C}$.