Both Diet Soda and regular soda contain sweeteners.
When a solute is dissolved in solution, the solution undergoes *freezing point depression* it freezing point reduces. The magnitude of freezing point depression is directly proportional to the amount of solute in a solution.
Since soda Both regular or diet soda contains more solute than water , their freezing point is will consequently be lower than water
Activation energy is the energy needed to start a reaction, eg the flame needed to start ... Collisions may have enough energy to react yet not react if the orientation of the molecules is incorrect. Difficult to explain here without graphics, but basically of the molecules are facing the wrong way it won't happen.
FeS2 is a reactant. When a reactant is added to a reaction which has already reached the equilibrium, more product is produced, so that the equilibrium is reestablished again
