question_answer

A block of ice at \[-\text{10}{{\,}^{\text{o}}}\text{C}\]is slowly heated and converted to steam at \[\text{100}{{\,}^{\text{o}}}\text{C}\text{.}\]Which of the following curves represents this phenomenon qualitatively?

A)                                                          

B)

C)                                                

D)

Correct Answer: A

Solution :

                 The temperature of ice will first increases from \[-10{{\,}^{o}}C\]to\[0{{\,}^{o}}C.\] Heat supplied in this process will be \[{{Q}_{1}}=m{{s}_{i}}(10)\] Here, m = mass of ice. Si = specific heat of ice Then ice starts melting. Temperature during melting will remain constant \[(0{{\,}^{o}}C).\] Heat  supplied in the process will be \[{{Q}_{2}}=mL\,L=\]latent heat of melting Now the temperature of water will increase from \[0{{\,}^{o}}C\]to \[{{100}^{o}}C.\] Heat supplied will be \[{{Q}_{3}}=m{{s}_{w}}(100){{s}_{w}}=\]specific heat of water Finally water at \[100{{\,}^{o}}C\]will be convened into steam at \[100{{\,}^{o}}C\]and during this process temperature   again   remains   constant.  Temperature versus heat supplied graph will be as follows: