Answers:
1. a) Nothing; b) position of equilibrium moves to left; c) position of equilibrium moves to the right.
2. a) Neutral; b) acidic; c) basic.
Explanation :
1. Le Châtelier’s Principle states that if you apply a stress to a system at equilibrium the system will respond in a way that will reduce the stress.
Here, the stress is the reduction of pressure. So the system will respond is a way that increased the pressure. That is, it will produce more moles of gas.
a) H₂(g) + Cl₂(g) ⇌ 2HCl(g)
Thee are two moles of gas on each side of the equation. Nothing the system does will increase the pressure, so nothing will happen.
b) 3O₂(g) ⇌ 2O₃(g)
There are more moles of gas on the left, so the position of equilibrium will move to the left.
c) CaCO₃(s) ⇌ CaO(s) + CO₂(g).
There are more moles of gas on the right, so the position of equilibrium will move to the right.
2. The conjugate base of a strong acid is neutral.
The conjugate acid of a strong base is neutral.
The conjugate base of a weak acid is basic.
The conjugate acid of a weak base is acidic.
a) NaCl
Salt of strong acid (HCl) and strong base (NaOH). Both ions are neutral.
b) NH₄NO₃
Salt of strong acid (HNO₃) and weak base (NH₃). NH₄⁺ is acidic.
c) (CH₃COO)₂Ca
Salt of weak acid (CH₃COOH) and strong base [Ca(OH)₂]. CH₃COO⁻ is basic.
