Take a bowl of ice, put it out in direct sunshine and note its temperature after every 05 minutes. What type of change in its temperature, do you observe? How much time will it take to melt completely? Now put the same water on a stove and note down its temperature after every 30 seconds. What type of change in its temperature, do you observe now? How much time will it take to boil? Explain your observations with the help of time and temperature chart. (Perform this experiment on a sunny day.)

Suppose a pair of chemical compounds a and b can react in two different ways: a + b -> c reaction 1 gives product c. a + b -> d reaction 2 gives product d. the following facts are known about the two reactions: . reaction 1 is endothermic and reaction 2 is exothermic. if a reaction vessel is charged (filled) with a and b , then at first d is produced faster than c. use these facts to sketch a qualitative reaction energy diagram for both reactions. note: because these sketches are only qualitative, the energies don? t have to be exact. they only have to have the right relationship to each other. for example, if one energy is less than another, that fact should be clear in your sketch.