During melting of ice, the temperature of the ice does not change until the ice melts. The heat is used up in :

Which of the following sulphides when  heated strongly in air gives the corresponding metal without undergoing separate reduction of oxide?

Which of the following is reactions is an example of autoreduction? 

When a solid melts, the temperature:

Heating the ore is in the presence of air is ?

Which of the following metal oxides are reduced by self reduction method?

When sunlight passes through the window of your house, the dust particles scatter the light making the path of the light visible. This phenomenon is called as________.

Out of $BaC{l}_2$ and $KCl$, which one is more effective in causing coagulation of a negatively charged colloidal sol? Give reason.

The diagram shows the changes in state of water ($H_{2}O$). What is the process X called :