Fuel cells are a particular type of electrochemical cell that require a constant source of chemical fuels, or reactants, during operation. One of the most common types of fuel cells is the alkaline fuel cell, which uses hydrogen and oxygen as reactants.
*(Both questions can have more than 1 answer)
What species are formed at the anode of the alkaline fuel cell?
What species are formed at the cathode of the alkaline fuel cell?
H2OChemistry4 months ago
Consider a galvanic cell in which Al3+ is reduced to elemental aluminum and magnesium metal is oxidized to Mg2+ . Write the balanced half-cell reactions that take place at the cathode and at the anode.
half-cell reaction at the cathode:
half-cell reaction at the anode:
Calculate the standard entropy, Δ𝑆∘rxn, of the reaction at 25.0 ∘C using the table of thermodynamic properties.
Calculate the standard Gibbs free energy of the reaction, Δ𝐺∘rxn. The standard enthalpy of the reaction, Δ𝐻∘rxn, is −44.2 kJ⋅mol−1.
Determine in which direction the reaction is spontaneous as written at 25.0 ∘C and standard pressure.
A critical reaction in the production of energy to do work or drive chemical reactions in biological systems is the hydrolysis of adenosine triphosphate, ATP, to adenosine diphosphate, ADP, as described by the reaction
1. for which Δ𝐺∘rxn=−30.5 kJ/mol at 37.0 °C and pH 7.0. Calculate the value of Δ𝐺rxn in a biological cell in which [ATP]=5.0 mM, [ADP]=0.80 mM, and [HPO2−4]=5.0 mM.
2. Is the hydrolysis of ATP spontaneous under these conditions?
The decomposition of a generic diatomic element in its standard state is represented by the equation
Assume that the standard molar Gibbs energy of formation of X(g) is 5.78 kJ·mol−1 at 2000. K and −63.70 kJ·mol−1 at 3000. K. Determine the value of the thermodynamic equilibrium constant, 𝐾 , at each temperature.
1. At 2000. K, Δ𝐺f=5.78 kJ·mol−1 . What is 𝐾 at that temperature?
𝐾 at 2000. K=
2. At 3000. K, Δ𝐺f=−63.70 kJ·mol−1 . What is K at that temperature?
𝐾 at 3000. K=
A strong base is dissolved in 755mL of 0.400M weak acid (Ka=3.93×10−5) to make a buffer with a pH of 3.96. Assume that the volume remains constant when the base is added.
1. Calculate the pKa value of the acid, and determine the number of moles of acid initially present.
initial amount: mol HA
2. When the reaction is complete, what is the concentration ratio of conjugate base to acid?
3. How many moles of strong base were initially added?
amount added: mol OH−1 AnswerChemistry5 months ago