
About 75 percent of hydrogen for industrial use is produced by the steam-reforming process. This process is carried out in two stages called primary and secondary reforming. In the primary stage, a mixture of steam and methane at about 30 atm is heated over a nickel catalyst at 800°C to give hydrogen and carbon monoxide:
The secondary stage is carried out at about 1000°C, in the presence of air, to convert the remaining methane to hydrogen:
(a) What conditions of temperature and pressure would favor the formation of products in both the primary and secondary stage? (b) The equilibrium constant Kc for the primary stage is 18 at 800°C. (i) Calculate KP for the reaction. (ii) If the partial pressures of methane and steam were both 15 atm at the start, what are the pressures of all the gases at equilibrium?
(a)

Interpretation:
The conditions of temperature and pressure which would favour the formation of products in both the primary and secondary stage has to be calculated using the data.
Concept Introduction:
Endothermic reaction:
In an endothermic reaction, heat will be a reactant. Therefore, increasing the temperature will shift the reaction from reactant side to the product side and the value of equilibrium constant will increases.
Exothermic reaction:
In an exothermic reaction, heat will be a product. Therefore, increasing the temperature will shift the reaction from product side to the reactant side and the value of equilibrium constant will decreases.
Explanation of Solution
Given data:
The reactions at primary stage and at the secondary stage are given below:
The reaction at primary stage has a temperature of
The both reactions are endothermic
If the reactions are endothermic, heat will be the reactant and high temperatures will favour the product side.
Therefore, high temperature is maintained at steam-reforming process.
Examining the reactions, it can be seen that number of moles of products is greater than the number of moles of reactants. Therefore, the expectation is that the products will be favoured at low pressures.
The reality is that the reactions are carried out at high pressures. It is for the production of higher yields of ammonia by the hydrogen gas produced which requires a high pressure.
(b)

Interpretation:
The equilibrium constant
Concept Introduction
Equilibrium constant at constant pressure:
It is used to express the relationship between product pressures and reactant pressures.
For a general reaction,
R- Gas constant
T- Temperature
Explanation of Solution
Given data:
The reaction is given below:
Equilibrium constant
The
The pressure of all the gases at equilibrium has to be calculated.
The amount of
The ICE table for the reaction is given below
Substituting the values in the equilibrium constant equation,
Taking the square root of both sides,
The value of x can be obtained by solving the quadratic equation
The pressure at equilibrium can be calculated as follows:
Want to see more full solutions like this?
Chapter 14 Solutions
Loose Leaf for Chemistry
- What are examples of analytical methods that can be used to analyse salt in tomato sauce?arrow_forwardA common alkene starting material is shown below. Predict the major product for each reaction. Use a dash or wedge bond to indicate the relative stereochemistry of substituents on asymmetric centers, where applicable. Ignore any inorganic byproducts H Šali OH H OH Select to Edit Select to Draw 1. BH3-THF 1. Hg(OAc)2, H2O =U= 2. H2O2, NaOH 2. NaBH4, NaOH + Please select a drawing or reagent from the question areaarrow_forwardWhat is the MOHR titration & AOAC method? What is it and how does it work? How can it be used to quantify salt in a sample?arrow_forward
- Predict the major products of this reaction. Cl₂ hv ? Draw only the major product or products in the drawing area below. If there's more than one major product, you can draw them in any arrangement you like. Be sure you use wedge and dash bonds if necessary, for example to distinguish between major products with different stereochemistry. If there will be no products because there will be no significant reaction, just check the box under the drawing area and leave it blank. Note for advanced students: you can ignore any products of repeated addition. Explanation Check Click and drag to start drawing a structure. 80 10 m 2025 McGraw Hill LLC. All Rights Reserved. Terms of Use | Privacy Center | Accessibility DII A F1 F2 F3 F4 F5 F6 F7 F8 EO F11arrow_forwardGiven a system with an anodic overpotential, the variation of η as a function of current density- at low fields is linear.- at higher fields, it follows Tafel's law.Calculate the range of current densities for which the overpotential has the same value when calculated for both cases (the maximum relative difference will be 5%, compared to the behavior for higher fields).arrow_forwardUsing reaction free energy to predict equilibrium composition Consider the following equilibrium: N2 (g) + 3H2 (g) = 2NH3 (g) AGº = -34. KJ Now suppose a reaction vessel is filled with 8.06 atm of nitrogen (N2) and 2.58 atm of ammonia (NH3) at 106. °C. Answer the following questions about this system: rise Under these conditions, will the pressure of N2 tend to rise or fall? ☐ x10 fall Is it possible to reverse this tendency by adding H₂? In other words, if you said the pressure of N2 will tend to rise, can that be changed to a tendency to fall by adding H2? Similarly, if you said the pressure of N will tend to fall, can that be changed to a tendency to rise by adding H₂? If you said the tendency can be reversed in the second question, calculate the minimum pressure of H₂ needed to reverse it. Round your answer to 2 significant digits. yes no ☐ atm Х ด ? olo 18 Ararrow_forward
- Four liters of an aqueous solution containing 6.98 mg of acetic acid were prepared. At 25°C, the measured conductivity was 5.89x10-3 mS cm-1. Calculate the degree of dissociation of the acid and its ionization constant.Molecular weights: O (15.999), C (12.011), H (1.008).Limiting molar ionic conductivities (λ+0 and λ-0) of Ac-(aq) and H+(aq): 40.9 and 349.8 S cm-2 mol-1.arrow_forwardDetermine the change in Gibbs energy, entropy, and enthalpy at 25°C for the battery from which the data in the table were obtained.T (°C) 15 20 25 30 35Eo (mV) 227.13 224.38 221.87 219.37 216.59Data: n = 1, F = 96485 C mol–1arrow_forwardIndicate the correct options.1. The units of the transport number are Siemens per mole.2. The Siemens and the ohm are not equivalent.3. The Van't Hoff factor is dimensionless.4. Molar conductivity does not depend on the electrolyte concentration.arrow_forward
- Ideally nonpolarizable electrodes can1. participate as reducers in reactions.2. be formed only with hydrogen.3. participate as oxidizers in reactions.4. form open and closed electrochemical systems.arrow_forwardIndicate the options for an electrified interface:1. Temperature has no influence on it.2. Not all theories that describe it include a well-defined electrical double layer.3. Under favorable conditions, its differential capacitance can be determined with the help of experimental measurements.4. A component with high electronic conductivity is involved in its formation.arrow_forwardTo describe the structure of the interface, there are theories or models that can be distinguished by:1. calculation of the charge density.2. distribution of ions in the solution.3. experimentally measured potential difference.4. external Helmoltz plane.arrow_forward
- Chemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage Learning
- General Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning





