Question

when two substances P&Q were combined to form a new substance S, the following observations were recorded:
(a) When P&Q combined large amount of heat is evolved
(b) The properties of S is different from P&Q.
From the above observations predict the nature of S and state its properties

Answer 1

In my thought S is carbon dioxide.It is in gaseous state.It is non combustible gas.
hope it helps....