Chemistry Le Chateliers Principle Question - Help Please!?

1.
Br₂(g) + Cl₂(g) ⇌ 2BrCl(g)

According to Le Chatelier's principle :
Adding Br₂ and Adding Cl₂ would shift the reaction to the right.
Removing Br2 and Removing Cl₂ would shift the reaction to the left.
Adding BrCl would shift the reaction to the left.
Removing BrCl would shift the reaction to the right.

Conclusively, to shift the reaction to the right, add Br₂, add Cl₂ or remove BrCl.
"Add Br₂ and remove BrCl" is the best answer.


2.
Pressure is increased when volume is reduced.
According to Le Chatelier's principle, the reaction would shift to a direction in order to decrease the number of gaseous molecules.
In the equation, there are 2 moles of gaseous molecules on the left, and also 2 moles of gaseous molecules on the right.
No matter what direction that the reaction shifts, the number of gaseous molecules is unchanged.
Therefore, there is no shift in the reaction.

"no change" is the best answer.


3.
pH = 3
[H+] = 1 × 10⁻³ M
[OH-] = Kw/[H+] = (1 × 10⁻¹⁴)/(1 × 10⁻³) = 1 × 10⁻¹¹ M

"1 × 10⁻¹¹ M" is the best answer.