Carbon tetrachloride is formed by the chlorination of methane at high temperature: The standard entropies and enthalpies of formation for the reactants and products are shown in the table.
|Material||Standard Molar Entropy (J/K⋅mol)||Standard Enthalpy of Formation (kJ/mol)|
Assuming the thermodynamic parameters do not vary with temperature, calculate, to 1 significant figure, the equilibrium constant for this reaction at .
Which of the following is the best definition of , the standard change in Gibbs free energy for a reversible process?
Consider the reaction . The equilibrium constant for this reaction at is 0.0120, and the value of at is 9.37 kJ. Given this information, what is the equilibrium constant for the reaction at , and what is the value of for the reaction? (You may assume that the of the reaction is independent of temperature.)
Hydrogen sulfide reacts reversibly with sulfur dioxide to form sulfur and water: The standard free energies of formation, , for hydrogen sulfide and other materials are shown in the table. These energies are measured at .
|Standard Gibbs Free Energy of Formation (kJ/mol)||0.0||238.3|
Calculate, to 2 significant figures, the equilibrium constant for this reaction at .
A student uses the values of at to calculate the equilibrium constant for this reaction at . Why are the results of this calculation likely to be inaccurate?
The standard change in Gibbs free energy for a reversible process, , is measured for a standard solution of reactants and products. What are the initial concentrations of the reactants and products in this solution?
The equilibrium constant for the hydrolysis of adenosine triphosphate (ATP) to adenosine diphosphate (ADP) and phosphate is at , and the for this reaction has a value of kJ/mol. Given this information, what is the value of for the reaction?
Consider the following two reactions: (1) , for which at ; and (2) , for which at . (In reaction (2), denotes adenosine triphosphate, denotes adenosine diphosphate, and represents inorganic phosphate.) These two reactions can be coupled by an enzyme catalyst (glutamine synthetase), which leads to the following reaction: (3) . What is the equilibrium constant for reaction (3) at a temperature of ?
Under certain conditions, gaseous ammonia can decompose into nitrogen and hydrogen gases: The partial pressures of , , and are denoted , , and respectively. When the initial partial pressure of each gas is equal to the standard value of 1.00 atm and the temperature is fixed at 298 K, the change in Gibbs free energy for the reaction, , is 33.00 kJ/mol. Calculate, to 3 significant figures, the change in Gibbs free energy, , at 298 K when , , and .