The equation for a reaction that occurs during the thermal decomposition of dinitrogen tetroxide is:
N2O4(g)⇌2NO2(g)ΔH=+57 kJ/mol \text{N}_2\text{O}_4(g) \rightleftharpoons 2\text{NO}_2(g) \quad \Delta H = +57\text{ kJ/mol} N2O4(g)⇌2NO2(g)ΔH=+57 kJ/mol(i) State the meanings of the symbols ⇌\rightleftharpoons⇌ and ΔH\Delta HΔH. (ii) What does the positive sign of ΔH\Delta HΔH indicate about the reaction?
Describe how to complete an energy level diagram for this reaction, specifying the relative vertical positions of the lines for the reactants and the products.
Typical conditions used to study this reaction in a laboratory are a temperature of 60∘C60^\circ\text{C}60∘C and a pressure of 3 atm3\text{ atm}3 atm. Deduce the effects of changing the conditions as shown below (choose from the words increased, decreased or unchanged): (1) Effect of an increase in temperature on the rate of reaction and on the yield of products; (2) Effect of the addition of a catalyst on the rate of reaction and on the yield of products.
A chemist considers carrying out the reaction at a pressure of 6 atm6\text{ atm}6 atm instead of 3 atm3\text{ atm}3 atm. (i) Predict and explain the effect on the rate of reaction of changing the pressure to 6 atm6\text{ atm}6 atm. (ii) Predict and explain the effect on the position of equilibrium of changing the pressure to 6 atm6\text{ atm}6 atm.
Balance the equation representing the reduction of nitrogen dioxide by carbon monoxide in a catalytic converter:
…NO2+…CO→…N2+…CO2 \dots\text{NO}_2 + \dots\text{CO} \rightarrow \dots\text{N}_2 + \dots\text{CO}_2 …NO2+…CO→…N2+…CO2
