Le Chatelier's Principle Quiz

Le Chaltelier's Principle states that if a chemical system at equilibrium is stressed,

• the system will adjust to increase the stress
• the system will adjust to reduce the stress
• the system will not adjust

For the reaction...
SO_2(g) + O_2(g) <−>  SO_3(g)
If the concentration of SO_2(g)  is increased, the equilibrium of the reaction will ___________.

• shift to the left
• shift to the right
• not shift

A +  B <--> C + D   ΔH= 151kJ
Rewrite the above equation with energy as a reactant or product:

• A +  B <--> C + D + energy
• A +  B + energy <--> C + D 

For the reaction...
heat  +  N_2(g)  +  O_2(g)  <−>  2NO_(g)
If the heat is removed to the chemical system, the equilibrium will _______.

• shift to the left
• shift to the right
• not shift

For the reaction...
N_{2 (g)} +  3 H_2 (g) <−> 2 NH_{3 (g)}

If the pressure in the system is increased, the reaction will __________________.

•  shift to the left
• shift to the right
• not shift

When  ΔH  is negative it represents a(n)

• exothermic reaction 
• endothermic reaction 

  A_(g) + B_(aq) <> C_(s) 
 ΔH_rxn= -453 kJ/mol
If the [B] is decreased then the reaction is will shift to the _______. 

• Left
• Right
• Stays the same 
• Up

Which is NOT a way to stress a closed chemical system at equilibrium?

• change temperature

• add a reactant

• take away a chemical in the reaction

• add a catalyst

Consider the following reaction: 
Heat  + 2NaClO_3(s) ⇌ 2NaCl_(s) + 3O_2(g)    Which of the following will cause a shift to the right?

• adding more O₂
• adding more NaCl
• removing some NaClO₃
• increasing the temperature

Predict the effect of decreasing the temperature on the position of the following equilibriums.
CO(g) + H₂O(g) ⇋CO₂(g) + H₂(g) 
 ΔH = -27.6 kJ

• shift left 
• shift right
• no shift
• the reaction is endothermic