The Contact process is used to convert sulfur dioxide and oxygen into sulfur trioxide.
Which raw material is the standard industrial source of the sulfur used to produce sulfur dioxide?
Gases used and produced in these chemical industries undergo several reversible reactions.
Reaction 1:
2SO2(g)+O2(g)⇌2SO3(g)ΔH=−197 kJ mol−1 2\text{SO}_2(\text{g}) + \text{O}_2(\text{g}) \rightleftharpoons 2\text{SO}_3(\text{g}) \quad \Delta H = -197 \text{ kJ mol}^{-1} 2SO2(g)+O2(g)⇌2SO3(g)ΔH=−197 kJ mol−1Reaction 2:
CO2(g)+H2(g)⇌CO(g)+H2O(g)ΔH=+41 kJ mol−1 \text{CO}_2(\text{g}) + \text{H}_2(\text{g}) \rightleftharpoons \text{CO}(\text{g}) + \text{H}_2\text{O}(\text{g}) \quad \Delta H = +41 \text{ kJ mol}^{-1} CO2(g)+H2(g)⇌CO(g)+H2O(g)ΔH=+41 kJ mol−1Predict what will happen to the equilibrium position in Reaction 1 when the pressure is increased. Give a reason for your prediction. Prediction: Reason:
Predict what will happen to the equilibrium position in Reaction 2 when the temperature is increased. Give a reason for your prediction. Prediction: Reason:
Predict what will happen to the rate of Reaction 1 when the pressure and temperature are increased. Effect of increased pressure: Effect of increased temperature:
Some of the sulfur trioxide is converted into sulfuric acid, which is then reacted with ammonia to produce ammonium phosphate fertilizer.
The equation for the formation of ammonium phosphate is:
3NH3+H3PO4→(NH4)3PO4 3\text{NH}_3 + \text{H}_3\text{PO}_4 \rightarrow (\text{NH}_4)_3\text{PO}_4 3NH3+H3PO4→(NH4)3PO4A manufacturer makes a batch of 89.4 kg89.4\text{ kg}89.4 kg of ammonium phosphate.
Calculate the amount, in moles, of (NH4)3PO4(\text{NH}_4)_3\text{PO}_4(NH4)3PO4 in 89.4 kg89.4\text{ kg}89.4 kg of ammonium phosphate. Amount of (NH4)3PO4(\text{NH}_4)_3\text{PO}_4(NH4)3PO4: _________ mol\text{mol}mol
Deduce the amount, in moles, of ammonia needed to make this amount of ammonium phosphate. Amount of ammonia: _________ mol\text{mol}mol
Calculate the mass, in kg, of ammonia needed. Mass of ammonia: _________ kg\text{kg}kg
Multi-nutrient fertilizers are often labelled with an NPK rating. Suggest the names of two elements, other than nitrogen, represented by these letters that are essential for plant growth.
28 exam-style questions on Edexcel IGCSE Chemistry Reversible reactions and equilibria. Each one has a worked solution and a mark scheme showing where the marks go.