The heating curve of a particular substance in solid state is as shows in the figure.Choose the correct alternative

If mass of the substance is 20 g then the heat energy required to melt 1 g the substacne is ______J.

Options

A. 300
B. 15
C. `113.50`
D. 2270

Answer

B

Explanation

The substance melts by absorbing 340 – 40 = 300 J of energy, i.e., 20 g of substance absorbs 300 J of energy and melts.
`therefore` Unit mass (1 g ) of substance absorbs `300/20`=15 J of energy and melts without rise in temperature .