Explain how an emission spectrum is produced.

answer:

emission spectra are produced by thin gases in which the atoms do not experience many collisions (because of the low density). the emission lines correspond to photons of discrete energies that are emitted when excited atomic states in the gas make transitions back to lower-lying levels.

explanation:

Based on Le Chatelier's principle, when the equilibrium of a given reaction is disturbed due to some external factors like temperature, pressure or concentration, the equilibrium shifts in a direction to undo the effects of the change produced.

The given reaction is :-

CaCO3 (s) ↔ CaO (g) + CO2(g)

The forward reaction involves the formation of CaO and CO2 while the reverse involves formation of CaCO3.

If the concentration of the products CaO and CO2 is increased then the equilibrium will shift to a direction to counteract this increase. Hence, the products will tend to get used up and the reverse reaction will be favored.

Ans: B) the rate of reverse reaction will increase if the concentration of caO and CO2 is increased.