Answer is: <span>lumps os sugar dissolving in water.
Sugar has very good solubility in water and it dissolves readily, which is </span><span>example of a physical change.
</span>Gibbs free energy (G) determines if reaction will proceed
spontaneously, if ΔG is negative, reaction is spontaneous <span>(ΔG = ΔH - T·ΔS).
</span>In other examples, reactions are spontaneous in reverse way, for example spontaneous is forming sodium chlorine from sodium metal and chlorine gas, but not sodium chloride forming sodium metal and chlorine gas, because a lot of energy is needed for that reaction.
Formula of isocyanic acid is HNCO. It colourless, volatile compound. It is poisonous inorganic compound. Melamine is synthesized from urea. The reaction involves two steps. In first step, urea gets converted to isocyanic acid which is an intermediate. In the second step, isocyanic acid gives melamine (molecular formula C₃H₆N₆) and carbon dioxide (CO₂). The balanced chemical reaction involved in second step is given below:
6 HNCO → 1 C₃N₃(NH₂)₃ + 3CO₂
The co-efficient of the reaction are: 6, 1, 3
