I think the last option is the correct answer. <span>The powder increased the hydrogen ion concentration of the solution. The said statement is the inference we can make from the situation. pH is the measure of hydrogen ions in a solution. The powder when added in the solution most likely dissociates into ions, especially hydrogen ions, thus decreasing the pH.</span>
They have high electron affinity
This is the correct equilibrium represented in the question
Blue + 4 Br- (aq) <---> green + 6H2O (l)
Answer:
Addition of NaBr supplied the Br- ions which moved the equilibrium position towards the right hand side. The forward reaction is endothermic hence its rate decreases when the reaction mixture is placed in an ice bath.
Explanation:
Blue + 4 Br- (aq) <---> green + 6H2O (l)
Looking at the equilibrium represented above, addition of Br- moves the equilibrium towards the right hand side, that is, the green colour. Addition of NaBr increases the Br- concentration and drives the forward reaction hence the equilibrium position shifts towards the right hand side. The fact that the solution turns blue when placed in ice bath reveals that the forward reaction is endothermic. Decreasing the temperature shifts the equilibrium position towards the left hence the resurgence of the blue colour.
Calcium will loose one electron. Fluorine will gain one electron. Lithium will loose one electron. Argon will not loose any because it already has a full valence level. Aluminium will loose 3 electrons.