
SL Paper 2
Consider the following equilibrium:
4NH3(g)+5O2(g)⇌4NO(g)+6H2O(g)ΔHΘ=−909 kJ
Nitrogen reacts with hydrogen to form ammonia in the Haber process, according to the following equilibrium.
N2(g)+3H2(g)⇌2NH3(g)ΔHΘ=−92.6 kJ
Deduce the equilibrium constant expression, Kc, for the reaction.
Predict the direction in which the equilibrium will shift when the following changes occur.
The volume increases.
The temperature decreases.
H2O(g) is removed from the system.
A catalyst is added to the reaction mixture.
Define the term activation energy, Ea.
Nitrogen monoxide, NO, is involved in the decomposition of ozone according to the following mechanism.
O3→O2+O∙O3+NO→NO2+O2NO2+O∙→NO+O2Overall:2O3→3O2
State and explain whether or not NO is acting as a catalyst.
Define the term endothermic reaction.
Sketch the Maxwell-Boltzmann energy distribution curve for a reaction with and without a catalyst, and label both axes.
Define the term rate of reaction.
Iron, used as the catalyst in the Haber process, has a specific heat capacity of 0.4490 Jg−1K−1. If 245.0 kJ of heat is supplied to 8.500 kg of iron, initially at a temperature of 15.25 °C, determine its final temperature in K.