Quiz #2

Open Notes, Open Neighbor

On a piece of paper put your Name, Student ID Number and Answer to:

Consider the following reaction:

As(s) + H2(g) → ← AsH3(g)

The reaction is allowed to come to equilibrium and then the pressure is increased by reducing the volume. Which direction does the reaction shift?

Answer

First, balance the reaction:

2 As(s) + 3 H2(g) → ← 2 AsH3(g)

Increasing the pressure will cause the reaction to shift to the side with fewer moles of gas, to reduce the total pressure in the system. This means the reaction will shift towards products (to the right).