Predict how temperature, pressure, concentration and catalysts affect the position and yield of reversible equilibria using the equilibrium equation and energy change.
Hydrogen iodide thermally decomposes into iodine and hydrogen. The reaction is reversible.
Fig. 4.1 shows a gas syringe containing a mixture of hydrogen iodide, iodine and hydrogen gases. The gas syringe is sealed and the mixture is heated to . The mixture of gases reaches equilibrium and is purple.
Fig. 4.1
The pressure of the mixture is increased. All other conditions stay the same. The position of equilibrium does not change.
The colour of the gaseous mixture turns darker purple.
The temperature remains constant.
Explain why the position of equilibrium does not change.
Suggest why the colour of the mixture of gases turns darker purple.
The temperature of the mixture of gases is decreased. All other conditions stay the same.
The mixture of gases turns lighter purple.
State what can be deduced about the forward reaction from this information.
Methanol is manufactured by reacting carbon monoxide with hydrogen.
The rate of formation of methanol increases when a catalyst is used.
State the effect on the position of equilibrium when a catalyst is used.