A block of ice at `-10^@C` is slowly heated and converted to steam at `100^@C.` Which of the following curves represents the phenomenon qualitatively?

Options

A.
B.
C.
D.

Answer

A

Explanation

The temperature of ice will first increase from `-10^(@)C "to" 0^(@)C`. Heat supplied in this process will be : `Q_(1) = mS_(i)(10)` m = mass of ice
`S_(i)` = specific heat of ice Then, ice starts melting
Temperature during melting will remain constant `(0^(@)C)`
Heat supplied in the process will be `Q_(2) = mL`
L = latent heat of melting Now the temperature of water from `0^(@)C "to" 100^(@)C`
Heat supplied will be `Q_(3) = mS_(W)(100)` where `S_(W)` = Specific heat of water
Finally water at `100^(@)C` will be converted into steam at `100^(@)C` and during this process temperature again remains constant. Temperature versus heat supplied graph will be as follows